NONCONTROLLING INTERESTS Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net income	$ 260,386	$ 347,226	$ (104,151)	$ (20,030)	$ 71,762	$ 56,444	$ 120,648	$ (23,336)	$ 483,431	$ 225,518	$ 195,533
Unrealized (loss) gain on available for sale securities									(24)	(42)	124
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax									(950)	(2,550)	1,982
Total other comprehensive (loss) income									(974)	(2,592)	2,106
Comprehensive income									482,457	222,926	197,639
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent									482,457	222,926	197,639
Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net income									415,517	170,811	146,401
Unrealized (loss) gain on available for sale securities									(23)	(41)	118
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax									(919)	(2,462)	1,887
Total other comprehensive (loss) income									(942)	(2,503)	2,005
Comprehensive income									414,575	168,308	148,406
Noncontrolling Interest [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net income									67,914	54,707	49,132
Unrealized (loss) gain on available for sale securities									(1)	(1)	6
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax									(31)	(88)	95
Total other comprehensive (loss) income									(32)	(89)	101
Comprehensive income									67,882	54,618	49,233
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Noncontrolling Interest									$ 67,882	$ 54,618	$ 49,233