Consolidated Statements of Income (USD $) In Thousands, except Per Share data, unless otherwise specified	1 Months Ended		3 Months Ended								12 Months Ended
	May 31, 2009	Mar. 31, 2009	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Operating revenues
Contract drilling services											$ 2,556,758	$ 2,695,493	$ 3,509,755
Reimbursables											79,195	76,831	99,201
Labor contract drilling services											59,004	32,520	30,298
Other											875	2,332	1,530
Total operating revenues			751,045	737,902	627,997	578,888	643,785	612,618	709,922	840,851	2,695,832	2,807,176	3,640,784
Operating costs and expenses
Contract drilling services											1,384,200	1,177,800	1,006,764
Reimbursables											58,439	59,414	85,035
Labor contract drilling services											33,885	22,056	18,827
Depreciation and amortization											658,640	539,829	408,313
Selling, general and administrative											91,377	91,997	80,262
Gain on contract extinguishments, net						52,500					(21,202)
Loss on asset disposal/involuntary conversion, net	17,000	12,000											30,839
Total operating costs and expenses											2,205,339	1,891,096	1,630,040
Operating income			161,602	163,582	79,045	86,264	116,215	108,357	268,547	422,961	490,493	916,080	2,010,744
Other income (expense)
Interest expense, net of amount capitalized											(55,727)	(9,457)	(1,685)
Interest income and other, net											1,484	9,886	6,843
Income before income taxes											436,250	916,509	2,015,902
Income tax provision											(72,625)	(143,077)	(337,260)
Net income											363,625	773,432	1,678,642
Income attributable to noncontrolling interests											7,273	(3)
Net income attributable to Noble Corporation			127,003	135,317	54,083	54,495	98,758	86,020	217,925	370,726	370,898	773,429	1,678,642
Net income per share attributable to Noble Corporation
Basic			$ 0.50	$ 0.53	$ 0.21	$ 0.22	$ 0.39	$ 0.34	$ 0.85	$ 1.44	$ 1.46	$ 3.03	$ 6.44
Diluted			$ 0.50	$ 0.53	$ 0.21	$ 0.21	$ 0.39	$ 0.34	$ 0.85	$ 1.43	$ 1.46	$ 3.02	$ 6.42
Weighted-Average Shares Outstanding:
Basic											251,405	253,123	258,035
Diluted											251,989	253,936	258,891
Noble-Cayman [Member]
Operating revenues
Contract drilling services											2,556,758	2,695,493	3,509,755
Reimbursables											79,195	76,831	99,201
Labor contract drilling services											59,004	32,520	30,298
Other											875	2,332	1,157
Total operating revenues											2,695,832	2,807,176	3,640,411
Operating costs and expenses
Contract drilling services											1,371,415	1,172,801	1,006,764
Reimbursables											58,439	59,414	85,035
Labor contract drilling services											33,885	22,056	18,827
Depreciation and amortization											657,205	539,004	408,313
Selling, general and administrative											56,787	55,568	58,543
Gain on contract extinguishments, net											(21,202)
Loss on asset disposal/involuntary conversion, net													30,839
Total operating costs and expenses											2,156,529	1,848,843	1,608,321
Operating income											539,303	958,333	2,032,090
Other income (expense)
Interest expense, net of amount capitalized											(55,727)	(9,457)	(1,685)
Interest income and other, net											2,480	8,527	6,810
Income before income taxes											486,056	957,403	2,037,215
Income tax provision											(71,286)	(141,866)	(336,834)
Net income											414,770	815,537	1,700,381
Income attributable to noncontrolling interests											7,273	(3)
Net income attributable to Noble Corporation											$ 422,043	$ 815,534	$ 1,700,381