OTHER COMPREHENSIVE INCOME (Amounts Reclassified from Accumulated Other Comprehensive Income to Earnings) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest expense									$ 130,155	$ 137,977	$ 295,522
Other nonoperating expense									9,243	13,000	13,357
Benefit from income taxes									135,198	105,449	(232,075)
Total	$ 141,092	$ 215,713	$ 197,558	$ 63,299	$ 124,023	$ 179,151	$ 159,652	$ 52,979	617,662	515,805	601,185
Reclassification From AOCI [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total									1,369	4,591	4,016
Reclassification Adjustment for Cash Flow Hedges [Member] | Reclassification From AOCI [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest expense									307	306	3,070
Benefit from income taxes									(80)	(80)	(1,208)
Total									227	226	1,862
Amortization of Pension and Postretirement Plan Actuarial Loss and Prior Service Cost [Member] | Reclassification From AOCI [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other nonoperating expense									1,545	5,906	2,915
Benefit from income taxes									(403)	(1,541)	(761)
Total									$ 1,142	$ 4,365	$ 2,154