OTHER COMPREHENSIVE INCOME (Amounts Reclassified from Accumulated Other Comprehensive Income to Earnings) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest expense									$ 135,960	$ 130,155	$ 137,977
Other nonoperating expense									(17,540)	9,243	13,000
Benefit from income taxes									155,803	135,198	105,449
Total	$ 114,518	$ 199,788	$ 209,916	$ 60,258	$ 141,092	$ 215,713	$ 197,558	$ 63,299	584,480	617,662	515,805
Reclassification From AOCI [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total									24,746	1,369	4,591
Reclassification Adjustment for Cash Flow Hedges [Member] | Reclassification From AOCI [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest expense									2,286	307	306
Benefit from income taxes									(597)	(80)	(80)
Total									1,689	227	226
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									31,200	1,545	5,906
Benefit from income taxes									(8,143)	(403)	(1,541)
Total									$ 23,057	$ 1,142	$ 4,365