GEOGRAPHIC AREA INFORMATION (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Revenues from External Customers and Long-Lived Assets [Line Items]
Consolidated Revenue	$ 1,392,607	$ 939,229	$ 1,017,705
Consolidated long-lived assets	6,071,729	5,678,713	4,344,522
Rigs under construction	756,245	711,558	937,609
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Consolidated Revenue	209,296	264,255	287,579
Consolidated long-lived assets	903,823	1,234,233	1,044,315
Saudi Arabia [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Consolidated Revenue	376,406	204,086	207,131
Consolidated long-lived assets	1,103,220	1,078,663	743,002
Norway [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Consolidated Revenue	131,251	73,829	80,717
Consolidated long-lived assets	495,518	501,447	202,773
Canada [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Consolidated Revenue	0	0	78,361
Consolidated long-lived assets	0	0	43,463
Qatar [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Consolidated Revenue	26,298	59,824	78,819
Consolidated long-lived assets	153,282	87,781	91,735
Egypt [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Consolidated Revenue	25,435	5,261	71,811
Consolidated long-lived assets	220,897	0	200,551
Angola [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Consolidated Revenue	0	0	68,543
United Kingdom [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Consolidated Revenue	385,174	230,638	99,111
Consolidated long-lived assets	1,555,324	1,562,942	822,335
Mexico [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Consolidated Revenue	0	27,977	45,633
Consolidated long-lived assets	0	0	54,307
Trinidad [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Consolidated Revenue	98,764	56,682	0
Consolidated long-lived assets	250,765	258,749	204,432
Malaysia [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Consolidated Revenue	88,960	6,776	0
Consolidated long-lived assets	447,949	45,039	0
Indonesia [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Consolidated Revenue	13,677	0	0
Consolidated long-lived assets	184,706	0	0
Vietnam [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Consolidated Revenue	37,346	9,901	0
Consolidated long-lived assets	0	198,205	0
Other Geographic Areas [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Consolidated long-lived assets	$ 0	$ 96	$ 0