PENSION AND OTHER POSTRETIREMENT BENEFITS - FAIR VALUE OF PLAN ASSETS (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 351,598	$ 330,987
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	330,987	312,497
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	$ 351,598	330,987
Pension Benefits | Minimum
Defined Benefit Plan Disclosure [Line Items]
Fund valuations lag period	90 days
Pension Benefits | Maximum
Defined Benefit Plan Disclosure [Line Items]
Fund valuations lag period	120 days
Pension Benefits | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 338,543	321,039
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	321,039
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	338,543	321,039
Pension Benefits | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	313,396	294,269
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	294,269
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	313,396	294,269
Pension Benefits | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	25,147	26,770
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	26,770
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	25,147	26,770
Pension Benefits | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0	2,756
Actual return on plan assets:
Relating to assets still held at the reporting date	0	0
Relating to assets sold during the period	0	0
Purchases, Sales and Settlements	0	(2,756)
Fair Value of Plan Assets at End of Year	0	0
Pension Benefits | Measured at net asset value practical expedient:
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	13,055	9,948
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	9,948
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	$ 13,055	9,948
Pension Benefits | Cash | Minimum
Actual return on plan assets:
Target plan allocation (as a percent)	0.00%
Pension Benefits | Cash | Maximum
Actual return on plan assets:
Target plan allocation (as a percent)	10.00%
Pension Benefits | Cash | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 1,299	881
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	881
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	1,299	881
Pension Benefits | Cash | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,299	881
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	881
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	1,299	881
Pension Benefits | Cash | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
Pension Benefits | Cash | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
Pension Benefits | STIF-Type Instrument | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	6,525	5,779
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	5,779
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	6,525	5,779
Pension Benefits | STIF-Type Instrument | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	6,525	5,779
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	5,779
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	6,525	5,779
Pension Benefits | STIF-Type Instrument | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
Pension Benefits | STIF-Type Instrument | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	$ 0	0
Pension Benefits | U.S equity securities | Minimum
Actual return on plan assets:
Target plan allocation (as a percent)	40.00%
Pension Benefits | U.S equity securities | Maximum
Actual return on plan assets:
Target plan allocation (as a percent)	70.00%
Pension Benefits | U.S. Large-Cap | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 100,095	100,322
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	100,322
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	100,095	100,322
Pension Benefits | U.S. Large-Cap | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	100,095	100,322
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	100,322
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	100,095	100,322
Pension Benefits | U.S. Large-Cap | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
Pension Benefits | U.S. Large-Cap | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
Pension Benefits | U.S. Mid-Cap | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	14,730	17,774
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	17,774
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	14,730	17,774
Pension Benefits | U.S. Mid-Cap | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	14,730	17,774
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	17,774
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	14,730	17,774
Pension Benefits | U.S. Mid-Cap | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
Pension Benefits | U.S. Mid-Cap | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
Pension Benefits | U.S. Small-Cap | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	13,639	14,938
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	14,938
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	13,639	14,938
Pension Benefits | U.S. Small-Cap | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	13,639	14,938
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	14,938
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	13,639	14,938
Pension Benefits | U.S. Small-Cap | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
Pension Benefits | U.S. Small-Cap | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
Pension Benefits | International equity securities | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	83,831	86,085
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	86,085
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	83,831	86,085
Pension Benefits | International equity securities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	83,831	86,085
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	86,085
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	83,831	86,085
Pension Benefits | International equity securities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
Pension Benefits | International equity securities | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	$ 0	0
Pension Benefits | Fixed income investments | Minimum
Actual return on plan assets:
Target plan allocation (as a percent)	25.00%
Pension Benefits | Fixed income investments | Maximum
Actual return on plan assets:
Target plan allocation (as a percent)	60.00%
Pension Benefits | Core Plus Fixed Income | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 49,510	54,066
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	54,066
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	49,510	54,066
Pension Benefits | Core Plus Fixed Income | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	24,363	27,296
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	27,296
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	24,363	27,296
Pension Benefits | Core Plus Fixed Income | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	25,147	26,770
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	26,770
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	25,147	26,770
Pension Benefits | Core Plus Fixed Income | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
Pension Benefits | Guaranteed Insurance Contract | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0	2,756
Actual return on plan assets:
Relating to assets still held at the reporting date	0	0
Relating to assets sold during the period	0	0
Purchases, Sales and Settlements	0	(2,756)
Fair Value of Plan Assets at End of Year	$ 0	0
Pension Benefits | Other investments | Minimum
Actual return on plan assets:
Target plan allocation (as a percent)	0.00%
Pension Benefits | Other investments | Maximum
Actual return on plan assets:
Target plan allocation (as a percent)	10.00%
Pension Benefits | Short Term Fixed | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 27,039
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	27,039
Pension Benefits | Short Term Fixed | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	27,039
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	27,039
Pension Benefits | Short Term Fixed | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0
Pension Benefits | Short Term Fixed | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0
Pension Benefits | Long Term Fixed | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	41,875	41,194
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	41,194
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	41,875	41,194
Pension Benefits | Long Term Fixed | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	41,875	41,194
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	41,194
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	41,875	41,194
Pension Benefits | Long Term Fixed | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
Pension Benefits | Long Term Fixed | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
Pension Benefits | Private Equity Funds | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0	0
Actual return on plan assets:
Relating to assets still held at the reporting date	0	0
Relating to assets sold during the period	0	0
Purchases, Sales and Settlements	0	0
Fair Value of Plan Assets at End of Year	0	0
Pension Benefits | Private Equity Funds | Measured at net asset value practical expedient:
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	13,055	9,948
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	9,948
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	13,055	9,948
Pension Benefits | Real Estate | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0	0
Actual return on plan assets:
Relating to assets still held at the reporting date	0	0
Relating to assets sold during the period	0	0
Purchases, Sales and Settlements	0	0
Fair Value of Plan Assets at End of Year	0	0
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	102,970	87,870
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	87,870	82,522
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	102,970	87,870
Other Postretirement Benefits | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	84,517	70,594
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	70,594
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	84,517	70,594
Other Postretirement Benefits | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	76,802	64,163
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	64,163
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	76,802	64,163
Other Postretirement Benefits | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7,715	6,431
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	6,431
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	7,715	6,431
Other Postretirement Benefits | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
Other Postretirement Benefits | Measured at net asset value practical expedient:
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	18,453	17,276
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	17,276
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	$ 18,453	17,276
Other Postretirement Benefits | Cash | Minimum
Actual return on plan assets:
Target plan allocation (as a percent)	0.00%
Other Postretirement Benefits | Cash | Maximum
Actual return on plan assets:
Target plan allocation (as a percent)	10.00%
Other Postretirement Benefits | Cash | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 292	2,334
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	2,334
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	292	2,334
Other Postretirement Benefits | Cash | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	292	2,334
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	2,334
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	292	2,334
Other Postretirement Benefits | Cash | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
Other Postretirement Benefits | Cash | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
Other Postretirement Benefits | STIF-Type Instrument | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,780
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	2,780
Other Postretirement Benefits | STIF-Type Instrument | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,780
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	2,780
Other Postretirement Benefits | STIF-Type Instrument | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0
Other Postretirement Benefits | STIF-Type Instrument | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	$ 0
Other Postretirement Benefits | U.S equity securities | Minimum
Actual return on plan assets:
Target plan allocation (as a percent)	55.00%
Other Postretirement Benefits | U.S equity securities | Maximum
Actual return on plan assets:
Target plan allocation (as a percent)	75.00%
Other Postretirement Benefits | U.S. Large-Cap | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 21,012	18,839
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	18,839
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	21,012	18,839
Other Postretirement Benefits | U.S. Large-Cap | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	21,012	18,839
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	18,839
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	21,012	18,839
Other Postretirement Benefits | U.S. Large-Cap | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
Other Postretirement Benefits | U.S. Large-Cap | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
Other Postretirement Benefits | U.S. Mid-Cap | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4,292	4,379
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	4,379
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	4,292	4,379
Other Postretirement Benefits | U.S. Mid-Cap | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4,292	4,379
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	4,379
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	4,292	4,379
Other Postretirement Benefits | U.S. Mid-Cap | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
Other Postretirement Benefits | U.S. Mid-Cap | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
Other Postretirement Benefits | U.S. Small-Cap | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7,380	3,361
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	3,361
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	7,380	3,361
Other Postretirement Benefits | U.S. Small-Cap | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7,380	3,361
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	3,361
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	7,380	3,361
Other Postretirement Benefits | U.S. Small-Cap | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
Other Postretirement Benefits | U.S. Small-Cap | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0
Other Postretirement Benefits | International equity securities | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	21,079	20,369
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	20,369
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	21,079	20,369
Other Postretirement Benefits | International equity securities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	21,079	20,369
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	20,369
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	21,079	20,369
Other Postretirement Benefits | International equity securities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
Other Postretirement Benefits | International equity securities | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	$ 0
Other Postretirement Benefits | Fixed income investments | Minimum
Actual return on plan assets:
Target plan allocation (as a percent)	25.00%
Other Postretirement Benefits | Fixed income investments | Maximum
Actual return on plan assets:
Target plan allocation (as a percent)	45.00%
Other Postretirement Benefits | Core Plus Fixed Income | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 14,958	6,431
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	6,431
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	14,958	6,431
Other Postretirement Benefits | Core Plus Fixed Income | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7,243	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	7,243	0
Other Postretirement Benefits | Core Plus Fixed Income | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7,715	6,431
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	6,431
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	7,715	6,431
Other Postretirement Benefits | Core Plus Fixed Income | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
Other Postretirement Benefits | Mutual Funds - Bonds | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	12,724	14,881
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	14,881
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	12,724	14,881
Other Postretirement Benefits | Mutual Funds - Bonds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	12,724	14,881
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	14,881
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	12,724	14,881
Other Postretirement Benefits | Mutual Funds - Bonds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
Other Postretirement Benefits | Mutual Funds - Bonds | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	$ 0	0
Other Postretirement Benefits | Other investments | Minimum
Actual return on plan assets:
Target plan allocation (as a percent)	0.00%
Other Postretirement Benefits | Other investments | Maximum
Actual return on plan assets:
Target plan allocation (as a percent)	10.00%
Other Postretirement Benefits | Company Owned Life Insurance | Measured at net asset value practical expedient:
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 18,453	17,276
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	17,276
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	18,453	17,276
South Jersey Gas Company | International equity securities | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year		0
South Jersey Gas Company | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	196,940	181,940
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	181,940	170,959
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	196,940	181,940
South Jersey Gas Company | Pension Benefits | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	186,605	174,002
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	174,002
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	186,605	174,002
South Jersey Gas Company | Pension Benefits | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	172,591	157,881
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	157,881
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	172,591	157,881
South Jersey Gas Company | Pension Benefits | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	14,014	16,121
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	16,121
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	14,014	16,121
South Jersey Gas Company | Pension Benefits | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0	2,216
Actual return on plan assets:
Relating to assets still held at the reporting date	0	0
Relating to assets sold during the period	0	0
Purchases, Sales and Settlements	0	(2,216)
Fair Value of Plan Assets at End of Year	0	0
South Jersey Gas Company | Pension Benefits | Measured at net asset value practical expedient:
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	10,335	7,938
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	7,938
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	10,335	7,938
South Jersey Gas Company | Pension Benefits | Cash | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	213	303
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	303
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	213	303
South Jersey Gas Company | Pension Benefits | Cash | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	213	303
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	303
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	213	303
South Jersey Gas Company | Pension Benefits | Cash | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
South Jersey Gas Company | Pension Benefits | Cash | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
South Jersey Gas Company | Pension Benefits | STIF-Type Instrument | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4,976	3,380
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	3,380
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	4,976	3,380
South Jersey Gas Company | Pension Benefits | STIF-Type Instrument | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4,976	3,380
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	3,380
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	4,976	3,380
South Jersey Gas Company | Pension Benefits | STIF-Type Instrument | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
South Jersey Gas Company | Pension Benefits | STIF-Type Instrument | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
South Jersey Gas Company | Pension Benefits | U.S. Large-Cap | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	54,651	52,346
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	52,346
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	54,651	52,346
South Jersey Gas Company | Pension Benefits | U.S. Large-Cap | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	54,651	52,346
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	52,346
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	54,651	52,346
South Jersey Gas Company | Pension Benefits | U.S. Large-Cap | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
South Jersey Gas Company | Pension Benefits | U.S. Large-Cap | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
South Jersey Gas Company | Pension Benefits | U.S. Mid-Cap | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7,632	8,138
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	8,138
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	7,632	8,138
South Jersey Gas Company | Pension Benefits | U.S. Mid-Cap | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7,632	8,138
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	8,138
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	7,632	8,138
South Jersey Gas Company | Pension Benefits | U.S. Mid-Cap | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
South Jersey Gas Company | Pension Benefits | U.S. Mid-Cap | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
South Jersey Gas Company | Pension Benefits | U.S. Small-Cap | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7,580	8,249
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	8,249
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	7,580	8,249
South Jersey Gas Company | Pension Benefits | U.S. Small-Cap | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7,580	8,249
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	8,249
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	7,580	8,249
South Jersey Gas Company | Pension Benefits | U.S. Small-Cap | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
South Jersey Gas Company | Pension Benefits | U.S. Small-Cap | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
South Jersey Gas Company | Pension Benefits | International equity securities | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	45,634	44,120
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	44,120
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	45,634	44,120
South Jersey Gas Company | Pension Benefits | International equity securities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	45,634	44,120
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	44,120
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	45,634	44,120
South Jersey Gas Company | Pension Benefits | International equity securities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
South Jersey Gas Company | Pension Benefits | International equity securities | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0
South Jersey Gas Company | Pension Benefits | Core Plus Fixed Income | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	27,592	32,571
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	32,571
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	27,592	32,571
South Jersey Gas Company | Pension Benefits | Core Plus Fixed Income | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	13,578	16,450
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	16,450
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	13,578	16,450
South Jersey Gas Company | Pension Benefits | Core Plus Fixed Income | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	14,014	16,121
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	16,121
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	14,014	16,121
South Jersey Gas Company | Pension Benefits | Core Plus Fixed Income | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
South Jersey Gas Company | Pension Benefits | Guaranteed Insurance Contract | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0	2,216
Actual return on plan assets:
Relating to assets still held at the reporting date	0	0
Relating to assets sold during the period	0	0
Purchases, Sales and Settlements	0	(2,216)
Fair Value of Plan Assets at End of Year	0	0
South Jersey Gas Company | Pension Benefits | Short Term Fixed | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	14,931
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	14,931
South Jersey Gas Company | Pension Benefits | Short Term Fixed | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	14,931
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	14,931
South Jersey Gas Company | Pension Benefits | Short Term Fixed | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0
South Jersey Gas Company | Pension Benefits | Short Term Fixed | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0
South Jersey Gas Company | Pension Benefits | Long Term Fixed | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	23,396	24,895
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	24,895
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	23,396	24,895
South Jersey Gas Company | Pension Benefits | Long Term Fixed | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	23,396	24,895
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	24,895
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	23,396	24,895
South Jersey Gas Company | Pension Benefits | Long Term Fixed | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
South Jersey Gas Company | Pension Benefits | Long Term Fixed | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
South Jersey Gas Company | Pension Benefits | Private Equity Funds | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0	0
Actual return on plan assets:
Relating to assets still held at the reporting date	0	0
Relating to assets sold during the period	0	0
Purchases, Sales and Settlements	0	0
Fair Value of Plan Assets at End of Year	0	0
South Jersey Gas Company | Pension Benefits | Private Equity Funds | Measured at net asset value practical expedient:
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	10,335	7,938
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	7,938
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	10,335	7,938
South Jersey Gas Company | Pension Benefits | Real Estate | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0	0
Actual return on plan assets:
Relating to assets still held at the reporting date	0	0
Relating to assets sold during the period	0	0
Purchases, Sales and Settlements	0	0
Fair Value of Plan Assets at End of Year	0	0
South Jersey Gas Company | Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	73,322	61,869
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	61,869	59,190
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	73,322	61,869
South Jersey Gas Company | Other Postretirement Benefits | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	55,922	45,660
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	45,660
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	55,922	45,660
South Jersey Gas Company | Other Postretirement Benefits | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	50,704	40,919
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	40,919
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	50,704	40,919
South Jersey Gas Company | Other Postretirement Benefits | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5,218	4,741
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	4,741
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	5,218	4,741
South Jersey Gas Company | Other Postretirement Benefits | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
South Jersey Gas Company | Other Postretirement Benefits | Measured at net asset value practical expedient:
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	17,400	16,209
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	16,209
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	17,400	16,209
South Jersey Gas Company | Other Postretirement Benefits | Cash | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	170	2,083
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	2,083
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	170	2,083
South Jersey Gas Company | Other Postretirement Benefits | Cash | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	170	2,083
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	2,083
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	170	2,083
South Jersey Gas Company | Other Postretirement Benefits | Cash | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
South Jersey Gas Company | Other Postretirement Benefits | Cash | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
South Jersey Gas Company | Other Postretirement Benefits | STIF-Type Instrument | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,616
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	2,616
South Jersey Gas Company | Other Postretirement Benefits | STIF-Type Instrument | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,616
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	2,616
South Jersey Gas Company | Other Postretirement Benefits | STIF-Type Instrument | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0
South Jersey Gas Company | Other Postretirement Benefits | STIF-Type Instrument | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0
South Jersey Gas Company | Other Postretirement Benefits | U.S. Large-Cap | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	16,101	10,764
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	10,764
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	16,101	10,764
South Jersey Gas Company | Other Postretirement Benefits | U.S. Large-Cap | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	16,101	10,764
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	10,764
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	16,101	10,764
South Jersey Gas Company | Other Postretirement Benefits | U.S. Large-Cap | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
South Jersey Gas Company | Other Postretirement Benefits | U.S. Large-Cap | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
South Jersey Gas Company | Other Postretirement Benefits | U.S. Mid-Cap | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,652	2,591
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	2,591
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	2,652	2,591
South Jersey Gas Company | Other Postretirement Benefits | U.S. Mid-Cap | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,652	2,591
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	2,591
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	2,652	2,591
South Jersey Gas Company | Other Postretirement Benefits | U.S. Mid-Cap | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
South Jersey Gas Company | Other Postretirement Benefits | U.S. Mid-Cap | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
South Jersey Gas Company | Other Postretirement Benefits | U.S. Small-Cap | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,115	2,200
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	2,200
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	2,115	2,200
South Jersey Gas Company | Other Postretirement Benefits | U.S. Small-Cap | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,115	2,200
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	2,200
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	2,115	2,200
South Jersey Gas Company | Other Postretirement Benefits | U.S. Small-Cap | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
South Jersey Gas Company | Other Postretirement Benefits | U.S. Small-Cap | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
South Jersey Gas Company | Other Postretirement Benefits | International equity securities | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	13,392	12,889
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	12,889
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	13,392	12,889
South Jersey Gas Company | Other Postretirement Benefits | International equity securities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	13,392	12,889
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	12,889
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	13,392	12,889
South Jersey Gas Company | Other Postretirement Benefits | International equity securities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
South Jersey Gas Company | Other Postretirement Benefits | International equity securities | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
South Jersey Gas Company | Other Postretirement Benefits | Core Plus Fixed Income | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	10,273	4,741
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	4,741
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	10,273	4,741
South Jersey Gas Company | Other Postretirement Benefits | Core Plus Fixed Income | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5,055	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	5,055	0
South Jersey Gas Company | Other Postretirement Benefits | Core Plus Fixed Income | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5,218	4,741
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	4,741
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	5,218	4,741
South Jersey Gas Company | Other Postretirement Benefits | Core Plus Fixed Income | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
South Jersey Gas Company | Other Postretirement Benefits | Mutual Funds - Bonds | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	8,603	10,392
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	10,392
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	8,603	10,392
South Jersey Gas Company | Other Postretirement Benefits | Mutual Funds - Bonds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	8,603	10,392
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	10,392
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	8,603	10,392
South Jersey Gas Company | Other Postretirement Benefits | Mutual Funds - Bonds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
South Jersey Gas Company | Other Postretirement Benefits | Mutual Funds - Bonds | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
South Jersey Gas Company | Other Postretirement Benefits | Company Owned Life Insurance | Measured at net asset value practical expedient:
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	17,400	16,209
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	16,209
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	$ 17,400	$ 16,209