GEOGRAPHIC AREA INFORMATION (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenues from External Customers and Long-Lived Assets [Line Items]
Consolidated revenues	$ 1,824,383	$ 1,579,284	$ 1,392,607
Consolidated long-lived assets	7,432,212	6,385,755	6,071,729
Rigs under construction	1,023,647	1,009,382	756,245
Saudi Arabia [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Consolidated revenues	443,873	412,799	376,406
Consolidated long-lived assets	932,714	1,204,915	1,103,220
United Kingdom [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Consolidated revenues	288,248	327,217	385,174
Consolidated long-lived assets	842,666	1,336,400	1,555,324
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Consolidated revenues	283,835	240,820	209,296
Consolidated long-lived assets	1,374,420	868,147	903,823
Norway [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Consolidated revenues	213,393	168,931	131,251
Consolidated long-lived assets	1,394,994	503,308	495,518
Malaysia [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Consolidated revenues	93,962	127,216	88,960
Consolidated long-lived assets	383,308	386,402	447,949
Angola [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Consolidated revenues	80,499	0	0
Consolidated long-lived assets	33	0	0
Netherlands [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Consolidated long-lived assets	0	270,409	0
Trinidad [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Consolidated revenues	94,722	101,262	98,764
Consolidated long-lived assets	238,697	254,671	250,765
Indonesia [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Consolidated revenues	125,851	90,027	13,677
Consolidated long-lived assets	221,512	251,169	184,706
Egypt [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Consolidated revenues	32,426	89,074	25,435
Consolidated long-lived assets	0	215,712	220,897
Namibia [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Consolidated revenues	25,479	0	0
Tunisia [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Consolidated revenues	18,590	0	0
Consolidated long-lived assets	214,790	0	0
Qatar [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Consolidated revenues	53,522	21,938	26,298
Consolidated long-lived assets	46,156	85,240	153,282
Spain [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Consolidated revenues	36,956	0	0
Consolidated long-lived assets	759,275	0	0
Morocco [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Consolidated revenues	33,027	0	0
Vietnam [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Consolidated revenues	$ 0	$ 0	$ 37,346