Guarantees of Registered Securities (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
CURRENT ASSETS: [Abstract]
Cash and cash equivalents	$ 328,290	$ 892,560	$ 328,290	$ 892,560
Restricted cash	0		0
Receivables - trade and other	403,465		403,465		283,592
Other current assets	107,794		107,794		71,609
Assets of discontinued operations	26,948		26,948		27,661
Total current assets	866,497		866,497		821,715
Property, plant and equipment - gross	7,547,032		7,547,032		7,029,322
Less accumulated depreciation and amortization	1,525,083		1,525,083		1,350,609
Property, plant and equipment - net	6,021,949		6,021,949		5,678,713
Investments in subsidiaries	0		0		0
Due from affiliates	0		0		0
Other assets	100,400		100,400		97,417
TOTAL ASSETS	6,988,846		6,988,846		6,597,845
CURRENT LIABILITIES: [Abstract]
Current maturities of long-term debt	0		0		45,023
Accounts payable - trade	90,101		90,101		111,082
Deferred revenues	35,975		35,975		36,220
Accrued liabilities	102,372		102,372		131,041
Liabilities of discontinued operations	21,255		21,255		25,005
Total current liabilities	249,703		249,703		348,371
Long-term debt - less current maturities	1,393,151		1,393,151		1,089,335
Due to affiliates	0		0		0
Other liabilities	380,430		380,430		357,709
Deferred income taxes - net	487,251		487,251		476,443
Shareholders' equity	4,478,311		4,478,311		4,325,987
TOTAL LIABILITIES AND EQUITY	6,988,846		6,988,846		6,597,845
Condensed Consolidating Income Statements [Abstract]
REVENUES	353,910	234,698	1,038,405	664,161
COSTS AND EXPENSES: [Abstract]
Direct operating costs (excluding items below)	188,152	129,767	558,405	345,558
Depreciation and amortization	63,027	50,306	183,323	129,267
Selling, general and administrative	25,780	22,629	73,934	65,172
Loss (gain) on disposals of property and equipment	(559)	14	(2,678)	(1,408)
Material charges and other operating expenses	18,174	20	30,871	6,120
Total costs and expenses	294,574	202,736	843,855	544,709
INCOME (LOSS) FROM OPERATIONS	59,336	31,962	194,550	119,452
OTHER INCOME (EXPENSE): [Abstract]
Interest expense, net of interest capitalized	(13,690)	(4,233)	(37,940)	(17,001)
Interest income	263	277	523	338
Loss on debt extinguishment	(10,456)	0	(22,223)	0
Other - net	(505)	(458)	710	(1,177)
Total other income (expense) - net	(24,388)	(4,414)	(58,930)	(17,840)
INCOME (LOSS) FROM CONTINUING OPERATIONS BEFORE INCOME TAXES	34,948	27,548	135,620	101,612
(Benefit) provision for income taxes	8,533	(3,876)	2,858	(1,010)
NET INCOME (LOSS) FROM CONTINUING OPERATIONS	26,415	31,424	132,762	102,622
DISCONTINUED OPERATIONS, NET OF TAX	1,164	162,385	(6,231)	589,118
EQUITY IN EARNINGS OF SUBSIDIARIES, NET OF TAX	0	0	0	0
NET INCOME	27,579	193,809	126,531	691,740
Statement of Comprehensive Income [Abstract]
NET INCOME	27,579	193,809	126,531	691,740
Pension and other postretirement benefit adjustments, net of income taxes
Amortization of net loss	4,131	0	12,305	0
Amortization of transition obligation	77	0	231	0
Amortization of prior service credit	(782)	0	(2,333)	0
OTHER COMPREHENSIVE INCOME	3,426	0	10,203	0
COMPREHENSIVE INCOME	31,005	193,809	136,734	691,740
Consolidated Statement of Cash Flows [Abstract]
NET CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES			189,502	128,009
INVESTING ACTIVITIES [Abstract]
Property, plant and equipment additions			(566,089)	(1,155,108)
Proceeds from disposals of property, plant and equipment			10,553	5,478
Proceeds from sale of manufacturing operations, net				1,560,538
Investments in consolidated subsidiaries			0	0
Change in restricted cash balance			0	15,265
Net cash provided by (used in) investing activities			(555,536)	426,173
FINANCING ACTIVITIES [Abstract]
Repayments of borrowings			(238,453)	(38,412)
Advances (to) from affiliates			0	0
Contributions from parent			0	0
Proceeds from borrowings			493,415	0
Debt issue costs			(799)	0
Dividends paid to affiliates			0
Proceeds from exercise of employee stock options			155	15,107
Payments to acquire treasury stock				(80,924)
Excess tax benefits from share-based compensation			1,153	5,128
Net cash provided by (used in) financing activities			255,471	(99,101)
INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS			(110,563)	455,081
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD			438,853	437,479
CASH AND CASH EQUIVALENTS, END OF PERIOD	328,290	892,560	328,290	892,560
Senior Notes due 2017 [Member]
Condensed Financial Statements, Captions [Line Items]
Stated interest rate (in hundredths)	5.00%		5.00%
Senior Notes due 2019 [Member]
Condensed Financial Statements, Captions [Line Items]
Stated interest rate (in hundredths)	7.875%		7.875%
Senior Notes due 2022 [Member]
Condensed Financial Statements, Captions [Line Items]
Stated interest rate (in hundredths)	4.875%		4.875%
Rowan UK [Member]
CURRENT ASSETS: [Abstract]
Cash and cash equivalents	72,819	0	72,819	0
Restricted cash	0		0
Receivables - trade and other	0		0		0
Other current assets	471		471		0
Assets of discontinued operations	0		0		0
Total current assets	73,290		73,290		21,472
Property, plant and equipment - gross	0		0		0
Less accumulated depreciation and amortization	0		0		0
Property, plant and equipment - net	0		0		0
Investments in subsidiaries	4,501,957		4,501,957		4,306,396
Due from affiliates	0		0		0
Other assets	0		0		0
TOTAL ASSETS	4,575,247		4,575,247		4,327,868
CURRENT LIABILITIES: [Abstract]
Current maturities of long-term debt					0
Accounts payable - trade	1,021		1,021		730
Deferred revenues	0		0		0
Accrued liabilities	(46)		(46)		0
Liabilities of discontinued operations	0		0		0
Total current liabilities	975		975		730
Long-term debt - less current maturities	0		0		0
Due to affiliates	95,961		95,961		1,151
Other liabilities	0		0		0
Deferred income taxes - net	0		0		0
Shareholders' equity	4,478,311		4,478,311		4,325,987
TOTAL LIABILITIES AND EQUITY	4,575,247		4,575,247		4,327,868
Condensed Consolidating Income Statements [Abstract]
REVENUES	0	0	0	0
COSTS AND EXPENSES: [Abstract]
Direct operating costs (excluding items below)	(162)	0	0	0
Depreciation and amortization	0	0	0	0
Selling, general and administrative	5,164	0	9,839	0
Loss (gain) on disposals of property and equipment	0	0	0	0
Material charges and other operating expenses	1,895	0	11,696	0
Total costs and expenses	6,897	0	21,535	0
INCOME (LOSS) FROM OPERATIONS	(6,897)	0	(21,535)	0
OTHER INCOME (EXPENSE): [Abstract]
Interest expense, net of interest capitalized	0	0	0	0
Interest income	36	0	46	0
Loss on debt extinguishment	0		0
Other - net	1	0	3	0
Total other income (expense) - net	37	0	49	0
INCOME (LOSS) FROM CONTINUING OPERATIONS BEFORE INCOME TAXES	(6,860)	0	(21,486)	0
(Benefit) provision for income taxes	0	0	0	0
NET INCOME (LOSS) FROM CONTINUING OPERATIONS	(6,860)	0	(21,486)	0
DISCONTINUED OPERATIONS, NET OF TAX	0	0	0	0
EQUITY IN EARNINGS OF SUBSIDIARIES, NET OF TAX	34,439	193,809	148,017	691,740
NET INCOME	27,579	193,809	126,531	691,740
Statement of Comprehensive Income [Abstract]
NET INCOME	27,579	193,809	126,531	691,740
Pension and other postretirement benefit adjustments, net of income taxes
Amortization of net loss	4,131	0	12,305	0
Amortization of transition obligation	77	0	231	0
Amortization of prior service credit	(782)	0	(2,333)	0
OTHER COMPREHENSIVE INCOME	3,426	0	10,203	0
COMPREHENSIVE INCOME	31,005	193,809	136,734	691,740
Consolidated Statement of Cash Flows [Abstract]
NET CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES			38,290	0
INVESTING ACTIVITIES [Abstract]
Property, plant and equipment additions			0	0
Proceeds from disposals of property, plant and equipment			0	0
Proceeds from sale of manufacturing operations, net				0
Investments in consolidated subsidiaries			0	0
Change in restricted cash balance				0
Net cash provided by (used in) investing activities			0	0
FINANCING ACTIVITIES [Abstract]
Repayments of borrowings			0	0
Advances (to) from affiliates			12,902	0
Contributions from parent			0	0
Proceeds from borrowings			0
Debt issue costs			0
Dividends paid to affiliates			0
Proceeds from exercise of employee stock options			155	0
Payments to acquire treasury stock				0
Excess tax benefits from share-based compensation			0	0
Net cash provided by (used in) financing activities			13,057	0
INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS			51,347	0
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD			21,472	0
CASH AND CASH EQUIVALENTS, END OF PERIOD	72,819	0	72,819	0
Rowan Delaware [Member]
CURRENT ASSETS: [Abstract]
Cash and cash equivalents	42,885	729,551	42,885	729,551
Restricted cash	0		0
Receivables - trade and other	33,352		33,352		33,380
Other current assets	48,967		48,967		46,137
Assets of discontinued operations	26,948		26,948		27,661
Total current assets	152,152		152,152		291,855
Property, plant and equipment - gross	1,335,097		1,335,097		1,290,526
Less accumulated depreciation and amortization	475,821		475,821		441,949
Property, plant and equipment - net	859,276		859,276		848,577
Investments in subsidiaries	1,420,157		1,420,157		1,101,982
Due from affiliates	3,959,273		3,959,273		3,732,488
Other assets	32,168		32,168		30,581
TOTAL ASSETS	6,423,026		6,423,026		6,005,483
CURRENT LIABILITIES: [Abstract]
Current maturities of long-term debt					22,464
Accounts payable - trade	21,522		21,522		43,091
Deferred revenues	0		0		0
Accrued liabilities	48,485		48,485		102,785
Liabilities of discontinued operations	21,255		21,255		25,005
Total current liabilities	91,262		91,262		193,345
Long-term debt - less current maturities	1,393,151		1,393,151		1,073,887
Due to affiliates	0		0		0
Other liabilities	313,581		313,581		303,117
Deferred income taxes - net	123,075		123,075		128,738
Shareholders' equity	4,501,957		4,501,957		4,306,396
TOTAL LIABILITIES AND EQUITY	6,423,026		6,423,026		6,005,483
Condensed Consolidating Income Statements [Abstract]
REVENUES	39,847	20,830	121,110	82,777
COSTS AND EXPENSES: [Abstract]
Direct operating costs (excluding items below)	7,487	13,183	21,776	61,133
Depreciation and amortization	13,915	14,889	40,588	44,022
Selling, general and administrative	99	5,764	10,009	17,019
Loss (gain) on disposals of property and equipment	(2,159)	(22)	(618)	(139)
Material charges and other operating expenses	8,962	20	10,319	6,120
Total costs and expenses	28,304	33,834	82,074	128,155
INCOME (LOSS) FROM OPERATIONS	11,543	(13,004)	39,036	(45,378)
OTHER INCOME (EXPENSE): [Abstract]
Interest expense, net of interest capitalized	(13,777)	(3,963)	(37,736)	(16,731)
Interest income	126	246	267	2,879
Loss on debt extinguishment	(10,423)		(21,603)
Other - net	(324)	9	(190)	55
Total other income (expense) - net	(24,398)	(3,708)	(59,262)	(13,797)
INCOME (LOSS) FROM CONTINUING OPERATIONS BEFORE INCOME TAXES	(12,855)	(16,712)	(20,226)	(59,175)
(Benefit) provision for income taxes	2,721	(2,464)	8,173	(15,189)
NET INCOME (LOSS) FROM CONTINUING OPERATIONS	(15,576)	(14,248)	(28,399)	(43,986)
DISCONTINUED OPERATIONS, NET OF TAX	1,164	163,598	(6,231)	588,071
EQUITY IN EARNINGS OF SUBSIDIARIES, NET OF TAX	48,851	44,459	182,647	147,655
NET INCOME	34,439	193,809	148,017	691,740
Statement of Comprehensive Income [Abstract]
NET INCOME	34,439	193,809	148,017	691,740
Pension and other postretirement benefit adjustments, net of income taxes
Amortization of net loss	4,131	0	12,305	0
Amortization of transition obligation	77	0	231	0
Amortization of prior service credit	(782)	0	(2,333)	0
OTHER COMPREHENSIVE INCOME	3,426	0	10,203	0
COMPREHENSIVE INCOME	37,865	193,809	158,220	691,740
Consolidated Statement of Cash Flows [Abstract]
NET CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES			78,317	(26,318)
INVESTING ACTIVITIES [Abstract]
Property, plant and equipment additions			(84,284)	(94,395)
Proceeds from disposals of property, plant and equipment			6,325	580
Proceeds from sale of manufacturing operations, net				1,560,538
Investments in consolidated subsidiaries			(175,858)	(628,580)
Change in restricted cash balance				0
Net cash provided by (used in) investing activities			(253,817)	838,143
FINANCING ACTIVITIES [Abstract]
Repayments of borrowings			(200,446)	(16,435)
Advances (to) from affiliates			(259,615)	(260,211)
Contributions from parent			0	0
Proceeds from borrowings			493,415
Debt issue costs			(799)
Dividends paid to affiliates			0
Proceeds from exercise of employee stock options			0	15,107
Payments to acquire treasury stock				(80,924)
Excess tax benefits from share-based compensation			1,153	5,128
Net cash provided by (used in) financing activities			33,708	(337,335)
INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS			(141,792)	474,490
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD			184,677	255,061
CASH AND CASH EQUIVALENTS, END OF PERIOD	42,885	729,551	42,885	729,551
Other non-guarantor subsidiaries [Member]
CURRENT ASSETS: [Abstract]
Cash and cash equivalents	212,586	163,009	212,586	163,009
Restricted cash	0		0
Receivables - trade and other	370,113		370,113		250,212
Other current assets	58,356		58,356		25,472
Assets of discontinued operations	0		0		0
Total current assets	641,055		641,055		508,388
Property, plant and equipment - gross	6,211,935		6,211,935		5,738,796
Less accumulated depreciation and amortization	1,049,262		1,049,262		908,660
Property, plant and equipment - net	5,162,673		5,162,673		4,830,136
Investments in subsidiaries	0		0		0
Due from affiliates	0		0		333,357
Other assets	68,232		68,232		66,836
TOTAL ASSETS	5,871,960		5,871,960		5,738,717
CURRENT LIABILITIES: [Abstract]
Current maturities of long-term debt					22,559
Accounts payable - trade	67,558		67,558		67,261
Deferred revenues	35,975		35,975		36,220
Accrued liabilities	53,933		53,933		28,256
Liabilities of discontinued operations	0		0		0
Total current liabilities	157,466		157,466		154,296
Long-term debt - less current maturities	0		0		15,448
Due to affiliates	3,863,312		3,863,312		4,064,694
Other liabilities	66,849		66,849		54,592
Deferred income taxes - net	364,176		364,176		347,705
Shareholders' equity	1,420,157		1,420,157		1,101,982
TOTAL LIABILITIES AND EQUITY	5,871,960		5,871,960		5,738,717
Condensed Consolidating Income Statements [Abstract]
REVENUES	347,176	225,393	1,018,233	624,584
COSTS AND EXPENSES: [Abstract]
Direct operating costs (excluding items below)	213,940	128,109	637,567	327,625
Depreciation and amortization	49,112	35,417	142,735	85,245
Selling, general and administrative	20,517	16,865	54,086	48,153
Loss (gain) on disposals of property and equipment	1,600	36	(2,060)	(1,269)
Material charges and other operating expenses	7,317	0	8,856	0
Total costs and expenses	292,486	180,427	841,184	459,754
INCOME (LOSS) FROM OPERATIONS	54,690	44,966	177,049	164,830
OTHER INCOME (EXPENSE): [Abstract]
Interest expense, net of interest capitalized	87	(270)	(204)	(2,921)
Interest income	101	31	210	110
Loss on debt extinguishment	(33)		(620)
Other - net	(182)	(467)	897	(1,232)
Total other income (expense) - net	(27)	(706)	283	(4,043)
INCOME (LOSS) FROM CONTINUING OPERATIONS BEFORE INCOME TAXES	54,663	44,260	177,332	160,787
(Benefit) provision for income taxes	5,812	(1,412)	(5,315)	14,179
NET INCOME (LOSS) FROM CONTINUING OPERATIONS	48,851	45,672	182,647	146,608
DISCONTINUED OPERATIONS, NET OF TAX	0	(1,213)	0	1,047
EQUITY IN EARNINGS OF SUBSIDIARIES, NET OF TAX	0	0	0	0
NET INCOME	48,851	44,459	182,647	147,655
Statement of Comprehensive Income [Abstract]
NET INCOME	48,851	44,459	182,647	147,655
Pension and other postretirement benefit adjustments, net of income taxes
Amortization of net loss	0	0	0	0
Amortization of transition obligation	0	0	0	0
Amortization of prior service credit	0	0	0	0
OTHER COMPREHENSIVE INCOME	0	0	0	0
COMPREHENSIVE INCOME	48,851	44,459	182,647	147,655
Consolidated Statement of Cash Flows [Abstract]
NET CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES			223,895	154,327
INVESTING ACTIVITIES [Abstract]
Property, plant and equipment additions			(481,805)	(1,060,713)
Proceeds from disposals of property, plant and equipment			4,228	4,898
Proceeds from sale of manufacturing operations, net				0
Investments in consolidated subsidiaries			0	0
Change in restricted cash balance				15,265
Net cash provided by (used in) investing activities			(477,577)	(1,040,550)
FINANCING ACTIVITIES [Abstract]
Repayments of borrowings			(38,007)	(21,977)
Advances (to) from affiliates			246,713	260,211
Contributions from parent			175,858	628,580
Proceeds from borrowings			0
Debt issue costs			0
Dividends paid to affiliates			(151,000)
Proceeds from exercise of employee stock options			0	0
Payments to acquire treasury stock				0
Excess tax benefits from share-based compensation			0	0
Net cash provided by (used in) financing activities			233,564	866,814
INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS			(20,118)	(19,409)
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD			232,704	182,418
CASH AND CASH EQUIVALENTS, END OF PERIOD	212,586	163,009	212,586	163,009
Consolidating adjustments [Member]
CURRENT ASSETS: [Abstract]
Cash and cash equivalents	0	0	0	0
Restricted cash	0		0
Receivables - trade and other	0		0		0
Other current assets	0		0		0
Assets of discontinued operations	0		0		0
Total current assets	0		0		0
Property, plant and equipment - gross	0		0		0
Less accumulated depreciation and amortization	0		0		0
Property, plant and equipment - net	0		0		0
Investments in subsidiaries	(5,922,114)		(5,922,114)		(5,408,378)
Due from affiliates	(3,959,273)		(3,959,273)		(4,065,845)
Other assets	0		0		0
TOTAL ASSETS	(9,881,387)		(9,881,387)		(9,474,223)
CURRENT LIABILITIES: [Abstract]
Current maturities of long-term debt					0
Accounts payable - trade	0		0		0
Deferred revenues	0		0		0
Accrued liabilities	0		0		0
Liabilities of discontinued operations	0		0		0
Total current liabilities	0		0		0
Long-term debt - less current maturities	0		0		0
Due to affiliates	(3,959,273)		(3,959,273)		(4,065,845)
Other liabilities	0		0		0
Deferred income taxes - net	0		0		0
Shareholders' equity	(5,922,114)		(5,922,114)		(5,408,378)
TOTAL LIABILITIES AND EQUITY	(9,881,387)		(9,881,387)		(9,474,223)
Condensed Consolidating Income Statements [Abstract]
REVENUES	(33,113)	(11,525)	(100,938)	(43,200)
COSTS AND EXPENSES: [Abstract]
Direct operating costs (excluding items below)	(33,113)	(11,525)	(100,938)	(43,200)
Depreciation and amortization	0	0	0	0
Selling, general and administrative	0	0	0	0
Loss (gain) on disposals of property and equipment	0	0	0	0
Material charges and other operating expenses	0	0	0	0
Total costs and expenses	(33,113)	(11,525)	(100,938)	(43,200)
INCOME (LOSS) FROM OPERATIONS	0	0	0	0
OTHER INCOME (EXPENSE): [Abstract]
Interest expense, net of interest capitalized	0	0	0	2,651
Interest income	0	0	0	(2,651)
Loss on debt extinguishment	0		0
Other - net	0	0	0	0
Total other income (expense) - net	0	0	0	0
INCOME (LOSS) FROM CONTINUING OPERATIONS BEFORE INCOME TAXES	0	0	0	0
(Benefit) provision for income taxes	0	0	0	0
NET INCOME (LOSS) FROM CONTINUING OPERATIONS	0	0	0	0
DISCONTINUED OPERATIONS, NET OF TAX	0	0	0	0
EQUITY IN EARNINGS OF SUBSIDIARIES, NET OF TAX	(83,290)	(238,268)	(330,664)	(839,395)
NET INCOME	(83,290)	(238,268)	(330,664)	(839,395)
Statement of Comprehensive Income [Abstract]
NET INCOME	(83,290)	(238,268)	(330,664)	(839,395)
Pension and other postretirement benefit adjustments, net of income taxes
Amortization of net loss	(4,131)	0	(12,305)	0
Amortization of transition obligation	(77)	0	(231)	0
Amortization of prior service credit	782	0	2,333	0
OTHER COMPREHENSIVE INCOME	(3,426)	0	(10,203)	0
COMPREHENSIVE INCOME	(86,716)	(238,268)	(340,867)	(839,395)
Consolidated Statement of Cash Flows [Abstract]
NET CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES			(151,000)	0
INVESTING ACTIVITIES [Abstract]
Property, plant and equipment additions			0	0
Proceeds from disposals of property, plant and equipment			0	0
Proceeds from sale of manufacturing operations, net				0
Investments in consolidated subsidiaries			175,858	628,580
Change in restricted cash balance				0
Net cash provided by (used in) investing activities			175,858	628,580
FINANCING ACTIVITIES [Abstract]
Repayments of borrowings			0	0
Advances (to) from affiliates			0	0
Contributions from parent			(175,858)	(628,580)
Proceeds from borrowings			0
Debt issue costs			0
Dividends paid to affiliates			151,000
Proceeds from exercise of employee stock options			0	0
Payments to acquire treasury stock				0
Excess tax benefits from share-based compensation			0	0
Net cash provided by (used in) financing activities			(24,858)	(628,580)
INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS			0	0
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD			0	0
CASH AND CASH EQUIVALENTS, END OF PERIOD	$ 0	$ 0	$ 0	$ 0