INCOME TAXES (Details) (USD $)	1 Months Ended	12 Months Ended
	Sep. 30, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Mar. 31, 2016
Operating Loss Carryforwards [Line Items]
Unrecognized tax benefits, net		$ 48,000,000	$ 75,000,000	$ 58,000,000
Unrecognized Tax Benefits that Would Impact Effective Tax Rate		48,000,000
Statutory rate		21.50%	23.25%	24.50%
Statutory income tax rate, UK		21.00%	23.00%	24.00%
Current:
U.S.		(62,332,000)	(38,025,000)	(69,934,000)
Non - U.S.		53,494,000	31,932,000	23,931,000
State		151,000	(5,141,000)	100,000
Current expense (benefit)		(8,687,000)	(11,234,000)	(45,903,000)
Deferred:
U.S.		(140,305,000)	20,827,000	45,794,000
Non - U.S.		(1,740,000)	(930,000)	(19,720,000)
Deferred provision (benefit)		(142,045,000)	19,897,000	26,074,000
Total provision (benefit)		(150,732,000)	8,663,000	(19,829,000)
Income tax expense (benefit), income tax reconciliation [Abstract]
U.K. Statutory rate		21.50%	23.25%	24.50%
Tax at statutory rate		(57,965,000)	60,738,000	44,950,000
Increase (decrease) due to:
Capitalized interest transactions		(20,145,000)	(11,317,000)	(39,204,000)
Foreign rate differential	36,000,000	10,449,000	0	0
Foreign rate differential		38,216,000	(27,078,000)	(27,591,000)
Deferred intercompany gain/loss		(86,635,000)	(9,062,000)	(8,749,000)
Change in valuation allowance		(3,570,000)	8,381,000	2,806,000
Prior period adjustments		7,511,000	(9,837,000)	4,482,000
Unrecognized tax benefits		(35,791,000)	17,544,000	2,463,000
Excess compensation		657,000	1,022,000	1,432,000
Foreign taxes of subsidiaries for which U.S. federal income taxes have been provided		0	9,155,000	0
Foreign tax credits/deductions		(4,925,000)	(31,078,000)	(1,632,000)
Other, net		1,466,000	195,000	1,214,000
Total provision (benefit)		(150,732,000)	8,663,000	(19,829,000)
Deferred tax assets, current
Accrued employee benefit plan costs		30,912,000	27,295,000
U.S. net operating loss		0	0
Other NOLs and tax credit carryforwards		819,000	0
Other		888,000	700,000
Total deferred tax assets		32,619,000	27,995,000
Less: valuation allowance		0	0
Deferred tax assets, net of valuation allowance		32,619,000	27,995,000
Deferred tax liabilities, current
Property, plant and equipment		0	0
Other		5,134,000	5,858,000
Total deferred tax liabilities		5,134,000	5,858,000
Net deferred tax asset (liability), current		27,485,000	22,137,000
Deferred tax assets, noncurrent
Accrued employee benefit plan costs		118,096,000	76,619,000
U.S. net operating loss		46,675,000	28,486,000
Other NOLs and tax credit carryforwards		23,634,000	0
Other		28,069,000	28,744,000
Total deferred tax assets		232,216,000	156,078,000
Less: valuation allowance		(22,339,000)	(25,909,000)
Deferred tax assets, net of valuation allowance		209,877,000	130,169,000
Deferred tax liabilities, noncurrent
Property, plant and equipment		369,095,000	514,612,000
Other		51,764,000	45,212,000
Total deferred tax liabilities		420,859,000	559,824,000
Net deferred tax asset (liability), noncurrent		(210,982,000)	(429,655,000)
Operating Loss Carryforwards
Significant decrease in unrecognized tax benefits due to anticipated settling of claims expected in the next 12 months		16,000,000
Changes in gross unrecognized tax benefits [Abstract]
Gross unrecognized tax benefits - beginning of year		81,920,000	58,900,000	55,300,000
Gross increases - tax positions in prior period		19,928,000	11,021,000	700,000
Gross decreases - tax positions in prior period		(10,649,000)	(4,114,000)	0
Gross increases - current period tax positions		9,458,000	16,674,000	2,900,000
Settlements		(37,809,000)	0	0
Lapse of statute of limitations		(8,188,000)	(561,000)	0
Gross unrecognized tax benefit - end of year		54,660,000	81,920,000	58,900,000
Accrued interest on income taxes		5,500,000	2,400,000	2,500,000
Accrued penalties on income taxes		2,600,000	1,700,000	1,400,000
INCOME (LOSS) FROM CONTINUING OPERATIONS
Income from continuing operations before income taxes, domestic		(198,300,000)	163,400,000	9,800,000
Income (loss) from continuing operations before income taxes, foreign		(71,300,000)	97,800,000	173,700,000
Foreign [Member]
Deferred tax assets, current
U.K. net operating loss		0	0
Deferred tax assets, noncurrent
U.K. net operating loss		2,708,000	8,280,000
Operating Loss Carryforwards
Net operating loss carryforwards		49,000,000
Non expiring NOLs		6,000,000
Operating loss carryforwards subject to valuation allowance		36,000,000
Non expiring NOLs subject to a valuation allowance		4,000,000
Undistributed Earnings of Foreign Subsidiaries		205,000,000
U.S. [Member]
Operating Loss Carryforwards
Net operating loss carryforwards, expiration dates		Dec. 31, 2032
U.K. [Member]
Operating Loss Carryforwards [Line Items]
Effective income tax rate		21.50%
Operating Loss Carryforwards
Non expiring NOLs		13,600,000
Operating loss carryforwards subject to valuation allowance		13,600,000
Trinidad [Member]
Deferred tax assets, current
U.K. net operating loss		0	0
Deferred tax assets, noncurrent
U.K. net operating loss		13,034,000	0
Operating Loss Carryforwards
Non expiring NOLs		52,000,000
Operating loss carryforwards subject to valuation allowance		25,000,000
Norway [Member]
Deferred tax assets, current
U.K. net operating loss		0	0
Deferred tax assets, noncurrent
U.K. net operating loss		0	13,949,000
Predecessor [Member]
Operating Loss Carryforwards [Line Items]
Statutory rate		35.00%
Income tax expense (benefit), income tax reconciliation [Abstract]
U.K. Statutory rate		35.00%
Forecast [Member]
Operating Loss Carryforwards [Line Items]
Statutory income tax rate, UK					20.00%
Expiring between 2035 and 2041 [Member] | U.S. [Member]
Operating Loss Carryforwards
Net operating loss carryforwards		$ 84,000,000