Consolidated Balance Sheet (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Current assets
Cash and cash equivalents	$ 239,196	$ 337,871
Accounts receivable	587,163	387,414
Taxes receivable	75,284	81,066
Prepaid expenses	57,254	35,502
Other current assets	100,715	69,941
Total current assets	1,059,612	911,794
Property and equipment
Drilling equipment and facilities	14,839,627	12,471,283
Other	197,485	172,583
Property and equipment, at cost	15,037,112	12,643,866
Accumulated depreciation	(3,139,645)	(2,595,779)
Property and equipment, net	11,897,467	10,048,087
Other assets	538,080	342,506
Total assets	13,495,159	11,302,387
Current liabilities
Current maturities of long-term debt	0	80,213
Accounts payable	436,006	374,814
Accrued payroll and related costs	117,907	125,663
Taxes payable	94,920	96,448
Interest payable	54,419	40,260
Other current liabilities	123,928	84,049
Total current liabilities	827,180	801,447
Long-term debt	4,071,964	2,686,484
Deferred income taxes	242,791	258,822
Other liabilities	255,372	268,000
Total liabilities	5,397,307	4,014,753
Commitments and contingencies
Equity
Shares; 252,639 shares and 262,415 shares outstanding	766,595	917,684
Treasury shares, at cost; 287 shares and 10,140 shares	(10,553)	(373,967)
Additional paid-in capital	48,356	39,006
Retained earnings	6,676,444	6,630,500
Accumulated other comprehensive loss	(74,321)	(50,220)
Total shareholders' equity	7,406,521	7,163,003
Noncontrolling interests	691,331	124,631
Total equity	8,097,852	7,287,634
Total liabilities and equity	13,495,159	11,302,387
Noble-Cayman [Member]
Current assets
Cash and cash equivalents	235,056	333,399
Accounts receivable	587,163	387,414
Taxes receivable	75,284	81,066
Prepaid expenses	54,563	33,232
Other current assets	98,651	69,821
Total current assets	1,050,717	904,932
Property and equipment
Drilling equipment and facilities	14,839,627	12,471,283
Other	163,301	143,691
Property and equipment, at cost	15,002,928	12,614,974
Accumulated depreciation	(3,134,401)	(2,594,954)
Property and equipment, net	11,868,527	10,020,020
Other assets	538,161	342,592
Total assets	13,457,405	11,267,544
Current liabilities
Current maturities of long-term debt	0	80,213
Accounts payable	435,729	374,559
Accrued payroll and related costs	108,908	120,634
Taxes payable	91,190	94,132
Interest payable	54,419	40,260
Other current liabilities	123,399	83,759
Total current liabilities	813,645	793,557
Long-term debt	4,071,964	2,686,484
Deferred income taxes	242,791	258,822
Other liabilities	255,372	268,026
Total liabilities	5,383,772	4,006,889
Commitments and contingencies
Equity
Ordinary shares; 261,246 shares outstanding	26,125	26,125
Additional paid-in capital	450,616	416,232
Retained earnings	6,979,882	6,743,887
Accumulated other comprehensive loss	(74,321)	(50,220)
Total shareholders' equity	7,382,302	7,136,024
Noncontrolling interests	691,331	124,631
Total equity	8,073,633	7,260,655
Total liabilities and equity	$ 13,457,405	$ 11,267,544