Guarantees of Registered Securities (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Dec. 31, 2014
CURRENT ASSETS:
Cash and cash equivalents	$ 290,481	$ 707,729	$ 339,154	$ 1,092,844	$ 290,481	$ 339,154
Receivables - trade and other					508,338	545,204
Other current assets					37,529	56,738
Total current assets					836,348	941,096
Property, plant and equipment - gross					9,033,428	8,800,182
Less accumulated depreciation and amortization					1,564,710	1,367,970
Property, plant and equipment - net					7,468,718	7,432,212
Investments in subsidiaries					0	0
Due from affiliates					0	0
Other assets					36,609	37,884
TOTAL ASSETS					8,341,675	8,411,192
CURRENT LIABILITIES:
Accounts payable - trade					118,976	102,773
Deferred revenues					48,204	36,189
Accrued liabilities					151,491	194,259
Total current liabilities					318,671	333,221
Long-term debt					2,806,686	2,807,324
Due to affiliates					0	0
Other liabilities					380,558	368,266
Deferred income taxes - net					190,822	210,982
Shareholders' equity					4,644,938	4,691,399
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY					8,341,675	8,411,192
Consolidating Income Statements
REVENUES	545,436	467,692	1,601,211	1,268,172
COSTS AND EXPENSES:
Direct operating costs (excluding items below)	247,642	246,907	757,320	711,854
Cost of Services, Depreciation and Amortization	104,109	81,503	289,189	230,054
Selling, general and administrative	29,671	33,040	88,415	92,057
Loss (gain) on disposals of property and equipment	2,250	58	2,075	1,720
Proceeds from litigation settlement	0	0	0	(20,875)
Material charges and other operating expenses	332,347	0	337,347	8,300
Total costs and expenses	716,019	361,508	1,474,346	1,023,110
INCOME (LOSS) FROM OPERATIONS	(170,583)	106,184	126,865	245,062
OTHER INCOME (EXPENSE):
Interest expense, net of interest capitalized	(41,344)	(25,656)	(104,930)	(74,308)
Interest income	230	372	820	1,721
Other - net	(1,754)	269	(2,875)	(627)
Total other income (expense) - net	(42,868)	(25,015)	(106,985)	(73,214)
INCOME (LOSS) FROM CONTINUING OPERATIONS BEFORE INCOME TAXES	(213,451)	81,169	19,880	171,848
Provision for income taxes	25,996	(38,428)	50,923	(36,165)
NET INCOME (LOSS) FROM CONTINUING OPERATIONS	(239,447)	119,597	(31,043)	208,013
DISCONTINUED OPERATIONS, NET OF TAX		0		4,023
EQUITY IN EARNINGS OF SUBSIDIARIES, NET OF TAX	0	0	0	0
Net income	(239,447)	119,597	(31,043)	212,036
Statement of Comprehensive Income [Abstract]
Net income	(239,447)	119,597	(31,043)	212,036
OTHER COMPREHENSIVE INCOME:
Net reclassification adjustments for amount recognized in net income as a component of net periodic benefit cost, net of income taxes	3,456	2,453	10,255	7,281
COMPREHENSIVE INCOME (LOSS)	(235,991)	122,050	(20,788)	219,317
Consolidated Statement of Cash Flows [Abstract]
NET CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES			658,871	200,222
INVESTING ACTIVITIES:
Property, plant and equipment additions			(674,816)	(1,367,414)
Proceeds from disposals of property, plant and equipment			5,144	9,767
Advances on subsidiary notes receivables			0
Collections on subsidiary notes receivables			0
Investments in consolidated subsidiaries			0	0
Net cash used in investing activities			(669,672)	(1,357,647)
FINANCING ACTIVITIES:
Advances (to) from affiliates			0	0
Contributions from parent			0	0
Proceeds from borrowings			220,000	793,380
Repayments of borrowings			(220,000)	0
Debt issue costs			0	(687)
Dividends paid			(37,872)	(25,123)
Excess tax benefit (deficit) from share-based compensation			0	15
Proceeds from exercise of share options			0	4,725
Net cash provided by (used in) financing activities			(37,872)	772,310
DECREASE IN CASH AND CASH EQUIVALENTS			(48,673)	(385,115)
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD			339,154	1,092,844
CASH AND CASH EQUIVALENTS, END OF PERIOD	290,481	707,729	290,481	707,729
Rowan Companies plc (Parent) [Member]
CURRENT ASSETS:
Cash and cash equivalents	793	90,014	45,909	64,292	793	45,909
Receivables - trade and other					110	26
Other current assets					572	424
Total current assets					1,475	46,359
Property, plant and equipment - gross					0	0
Less accumulated depreciation and amortization					0	0
Property, plant and equipment - net					0	0
Investments in subsidiaries					4,618,762	4,624,874
Due from affiliates					31,038	36,586
Other assets					0	0
TOTAL ASSETS					4,651,275	4,707,819
CURRENT LIABILITIES:
Accounts payable - trade					1,488	912
Deferred revenues					0	0
Accrued liabilities					630	400
Total current liabilities					2,118	1,312
Long-term debt					0	0
Due to affiliates					128	9,282
Other liabilities					4,091	5,826
Deferred income taxes - net					0	0
Shareholders' equity					4,644,938	4,691,399
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY					4,651,275	4,707,819
Consolidating Income Statements
REVENUES	0	0	0	0
COSTS AND EXPENSES:
Direct operating costs (excluding items below)	0	0	0	0
Cost of Services, Depreciation and Amortization	0	0	0	0
Selling, general and administrative	5,433	6,020	16,651	17,563
Loss (gain) on disposals of property and equipment	0	0	0	0
Proceeds from litigation settlement				0
Material charges and other operating expenses	0	0	0	0
Total costs and expenses	5,433	6,020	16,651	17,563
INCOME (LOSS) FROM OPERATIONS	(5,433)	(6,020)	(16,651)	(17,563)
OTHER INCOME (EXPENSE):
Interest expense, net of interest capitalized	0	0	0	0
Interest income	495	71	753	274
Other - net	5,599	9,798	16,804	16,798
Total other income (expense) - net	6,094	9,869	17,557	17,072
INCOME (LOSS) FROM CONTINUING OPERATIONS BEFORE INCOME TAXES	661	3,849	906	(491)
Provision for income taxes	0	0	0	0
NET INCOME (LOSS) FROM CONTINUING OPERATIONS	661	3,849	906	(491)
DISCONTINUED OPERATIONS, NET OF TAX		0		0
EQUITY IN EARNINGS OF SUBSIDIARIES, NET OF TAX	(240,108)	115,748	(31,949)	212,527
Net income	(239,447)	119,597	(31,043)	212,036
Statement of Comprehensive Income [Abstract]
Net income	(239,447)	119,597	(31,043)	212,036
OTHER COMPREHENSIVE INCOME:
Net reclassification adjustments for amount recognized in net income as a component of net periodic benefit cost, net of income taxes	3,456	2,453	10,255	7,281
COMPREHENSIVE INCOME (LOSS)	(235,991)	122,050	(20,788)	219,317
Consolidated Statement of Cash Flows [Abstract]
NET CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES			(3,776)	66,891
INVESTING ACTIVITIES:
Property, plant and equipment additions			0	0
Proceeds from disposals of property, plant and equipment			0	0
Advances on subsidiary notes receivables			0
Collections on subsidiary notes receivables			7,000
Investments in consolidated subsidiaries			0	0
Net cash used in investing activities			7,000	0
FINANCING ACTIVITIES:
Advances (to) from affiliates			(10,468)	(20,771)
Contributions from parent			0	0
Proceeds from borrowings			0	0
Repayments of borrowings			0
Debt issue costs				0
Dividends paid			(37,872)	(25,123)
Excess tax benefit (deficit) from share-based compensation				0
Proceeds from exercise of share options				4,725
Net cash provided by (used in) financing activities			(48,340)	(41,169)
DECREASE IN CASH AND CASH EQUIVALENTS			(45,116)	25,722
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD			45,909	64,292
CASH AND CASH EQUIVALENTS, END OF PERIOD	793	90,014	793	90,014
RCI (Issuer) [Member]
CURRENT ASSETS:
Cash and cash equivalents	18,156	62,574	48,580	92,116	18,156	48,580
Receivables - trade and other					2,673	4,317
Other current assets					25,842	47,986
Total current assets					46,671	100,883
Property, plant and equipment - gross					576,017	610,063
Less accumulated depreciation and amortization					236,711	271,293
Property, plant and equipment - net					339,306	338,770
Investments in subsidiaries					5,998,404	5,863,509
Due from affiliates					1,341,153	1,412,860
Other assets					20,460	18,103
TOTAL ASSETS					7,745,994	7,734,125
CURRENT LIABILITIES:
Accounts payable - trade					13,755	8,576
Deferred revenues					0	0
Accrued liabilities					95,938	100,167
Total current liabilities					109,693	108,743
Long-term debt					2,806,686	2,807,324
Due to affiliates					59,020	45,457
Other liabilities					321,216	312,575
Deferred income taxes - net					517,450	507,281
Shareholders' equity					3,931,929	3,952,745
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY					7,745,994	7,734,125
Consolidating Income Statements
REVENUES	15,886	17,437	49,222	46,854
COSTS AND EXPENSES:
Direct operating costs (excluding items below)	946	(2,247)	5,816	7,243
Cost of Services, Depreciation and Amortization	6,819	3,439	14,787	13,152
Selling, general and administrative	(1,690)	319	375	3,650
Loss (gain) on disposals of property and equipment	482	74	486	402
Proceeds from litigation settlement				0
Material charges and other operating expenses	0	0	0	0
Total costs and expenses	6,557	1,585	21,464	24,447
INCOME (LOSS) FROM OPERATIONS	9,329	15,852	27,758	22,407
OTHER INCOME (EXPENSE):
Interest expense, net of interest capitalized	(41,344)	(25,657)	(104,930)	(74,309)
Interest income	13,186	746	19,753	1,746
Other - net	(5,642)	(9,793)	(16,760)	(16,782)
Total other income (expense) - net	(33,800)	(34,704)	(101,937)	(89,345)
INCOME (LOSS) FROM CONTINUING OPERATIONS BEFORE INCOME TAXES	(24,471)	(18,852)	(74,179)	(66,938)
Provision for income taxes	24,898	(27,095)	27,305	(48,367)
NET INCOME (LOSS) FROM CONTINUING OPERATIONS	(49,369)	8,243	(101,484)	(18,571)
DISCONTINUED OPERATIONS, NET OF TAX		0		4,023
EQUITY IN EARNINGS OF SUBSIDIARIES, NET OF TAX	(182,064)	34,944	(158,557)	52,525
Net income	(231,433)	43,187	(260,041)	37,977
Statement of Comprehensive Income [Abstract]
Net income	(231,433)	43,187	(260,041)	37,977
OTHER COMPREHENSIVE INCOME:
Net reclassification adjustments for amount recognized in net income as a component of net periodic benefit cost, net of income taxes	3,456	2,453	10,255	7,281
COMPREHENSIVE INCOME (LOSS)	(227,977)	45,640	(249,786)	45,258
Consolidated Statement of Cash Flows [Abstract]
NET CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES			22,571	294,344
INVESTING ACTIVITIES:
Property, plant and equipment additions			(14,836)	(15,995)
Proceeds from disposals of property, plant and equipment			2,836	6,955
Advances on subsidiary notes receivables			(481,300)
Collections on subsidiary notes receivables			434,190
Investments in consolidated subsidiaries			(36,704)	(105,261)
Net cash used in investing activities			(95,814)	(114,301)
FINANCING ACTIVITIES:
Advances (to) from affiliates			42,819	(927,293)
Contributions from parent			0	0
Proceeds from borrowings			220,000	793,380
Repayments of borrowings			(220,000)
Debt issue costs				(687)
Dividends paid			0	(75,000)
Excess tax benefit (deficit) from share-based compensation				15
Proceeds from exercise of share options				0
Net cash provided by (used in) financing activities			42,819	(209,585)
DECREASE IN CASH AND CASH EQUIVALENTS			(30,424)	(29,542)
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD			48,580	92,116
CASH AND CASH EQUIVALENTS, END OF PERIOD	18,156	62,574	18,156	62,574
Other non-guarantor subsidiaries [Member]
CURRENT ASSETS:
Cash and cash equivalents	271,532	555,141	244,665	936,436	271,532	244,665
Receivables - trade and other					505,555	540,861
Other current assets					11,115	8,328
Total current assets					788,202	793,854
Property, plant and equipment - gross					8,457,411	8,190,119
Less accumulated depreciation and amortization					1,327,999	1,096,677
Property, plant and equipment - net					7,129,412	7,093,442
Investments in subsidiaries					0	0
Due from affiliates					57,793	71,867
Other assets					16,149	19,781
TOTAL ASSETS					7,991,556	7,978,944
CURRENT LIABILITIES:
Accounts payable - trade					103,733	93,285
Deferred revenues					48,204	36,189
Accrued liabilities					54,923	93,692
Total current liabilities					206,860	223,166
Long-term debt					0	0
Due to affiliates					1,370,836	1,466,574
Other liabilities					55,251	49,865
Deferred income taxes - net					142,872	167,094
Shareholders' equity					6,215,737	6,072,245
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY					7,991,556	7,978,944
Consolidating Income Statements
REVENUES	543,591	468,013	1,600,037	1,269,101
COSTS AND EXPENSES:
Direct operating costs (excluding items below)	259,448	266,104	795,998	749,886
Cost of Services, Depreciation and Amortization	97,189	78,213	273,588	217,403
Selling, general and administrative	27,318	27,360	75,757	72,851
Loss (gain) on disposals of property and equipment	1,768	(16)	1,589	1,318
Proceeds from litigation settlement				(20,875)
Material charges and other operating expenses	332,347	0	337,347	8,300
Total costs and expenses	718,070	371,661	1,484,279	1,028,883
INCOME (LOSS) FROM OPERATIONS	(174,479)	96,352	115,758	240,218
OTHER INCOME (EXPENSE):
Interest expense, net of interest capitalized	(13,914)	(713)	(20,455)	(1,304)
Interest income	463	269	769	1,006
Other - net	(1,711)	264	(2,919)	(643)
Total other income (expense) - net	(15,162)	(180)	(22,605)	(941)
INCOME (LOSS) FROM CONTINUING OPERATIONS BEFORE INCOME TAXES	(189,641)	96,172	93,153	239,277
Provision for income taxes	(11,764)	252	30,452	37,618
NET INCOME (LOSS) FROM CONTINUING OPERATIONS	(177,877)	95,920	62,701	201,659
DISCONTINUED OPERATIONS, NET OF TAX		0		0
EQUITY IN EARNINGS OF SUBSIDIARIES, NET OF TAX	0	0	0	0
Net income	(177,877)	95,920	62,701	201,659
Statement of Comprehensive Income [Abstract]
Net income	(177,877)	95,920	62,701	201,659
OTHER COMPREHENSIVE INCOME:
Net reclassification adjustments for amount recognized in net income as a component of net periodic benefit cost, net of income taxes	0	0	0	0
COMPREHENSIVE INCOME (LOSS)	(177,877)	95,920	62,701	201,659
Consolidated Statement of Cash Flows [Abstract]
NET CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES			687,535	432,075
INVESTING ACTIVITIES:
Property, plant and equipment additions			(659,980)	(1,351,419)
Proceeds from disposals of property, plant and equipment			2,308	2,812
Advances on subsidiary notes receivables			0
Collections on subsidiary notes receivables			0
Investments in consolidated subsidiaries			0	0
Net cash used in investing activities			(657,672)	(1,348,607)
FINANCING ACTIVITIES:
Advances (to) from affiliates			(30,810)	532,376
Contributions from parent			36,704	105,261
Proceeds from borrowings			481,300	0
Repayments of borrowings			(441,190)
Debt issue costs				0
Dividends paid			(49,000)	(102,400)
Excess tax benefit (deficit) from share-based compensation				0
Proceeds from exercise of share options				0
Net cash provided by (used in) financing activities			(2,996)	535,237
DECREASE IN CASH AND CASH EQUIVALENTS			26,867	(381,295)
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD			244,665	936,436
CASH AND CASH EQUIVALENTS, END OF PERIOD	271,532	555,141	271,532	555,141
Consolidating adjustments [Member]
CURRENT ASSETS:
Cash and cash equivalents	0	0	0	0	0	0
Receivables - trade and other					0	0
Other current assets					0	0
Total current assets					0	0
Property, plant and equipment - gross					0	0
Less accumulated depreciation and amortization					0	0
Property, plant and equipment - net					0	0
Investments in subsidiaries					(10,617,166)	(10,488,383)
Due from affiliates					(1,429,984)	(1,521,313)
Other assets					0	0
TOTAL ASSETS					(12,047,150)	(12,009,696)
CURRENT LIABILITIES:
Accounts payable - trade					0	0
Deferred revenues					0	0
Accrued liabilities					0	0
Total current liabilities					0	0
Long-term debt					0	0
Due to affiliates					(1,429,984)	(1,521,313)
Other liabilities					0	0
Deferred income taxes - net					(469,500)	(463,393)
Shareholders' equity					(10,147,666)	(10,024,990)
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY					$ (12,047,150)	$ (12,009,696)
Consolidating Income Statements
REVENUES	(14,041)	(17,758)	(48,048)	(47,783)
COSTS AND EXPENSES:
Direct operating costs (excluding items below)	(12,752)	(16,950)	(44,494)	(45,275)
Cost of Services, Depreciation and Amortization	101	(149)	814	(501)
Selling, general and administrative	(1,390)	(659)	(4,368)	(2,007)
Loss (gain) on disposals of property and equipment	0	0	0	0
Proceeds from litigation settlement				0
Material charges and other operating expenses	0	0	0	0
Total costs and expenses	(14,041)	(17,758)	(48,048)	(47,783)
INCOME (LOSS) FROM OPERATIONS	0	0	0	0
OTHER INCOME (EXPENSE):
Interest expense, net of interest capitalized	13,914	714	20,455	1,305
Interest income	(13,914)	(714)	(20,455)	(1,305)
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
Provision for income taxes	12,862	(11,585)	(6,834)	(25,416)
NET INCOME (LOSS) FROM CONTINUING OPERATIONS	(12,862)	11,585	6,834	25,416
DISCONTINUED OPERATIONS, NET OF TAX		0		0
EQUITY IN EARNINGS OF SUBSIDIARIES, NET OF TAX	422,172	(150,692)	190,506	(265,052)
Net income	409,310	(139,107)	197,340	(239,636)
Statement of Comprehensive Income [Abstract]
Net income	409,310	(139,107)	197,340	(239,636)
OTHER COMPREHENSIVE INCOME:
Net reclassification adjustments for amount recognized in net income as a component of net periodic benefit cost, net of income taxes	(3,456)	(2,453)	(10,255)	(7,281)
COMPREHENSIVE INCOME (LOSS)	405,854	(141,560)	187,085	(246,917)
Consolidated Statement of Cash Flows [Abstract]
NET CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES			(47,459)	(593,088)
INVESTING ACTIVITIES:
Property, plant and equipment additions			0	0
Proceeds from disposals of property, plant and equipment			0	0
Advances on subsidiary notes receivables			481,300
Collections on subsidiary notes receivables			(441,190)
Investments in consolidated subsidiaries			36,704	105,261
Net cash used in investing activities			76,814	105,261
FINANCING ACTIVITIES:
Advances (to) from affiliates			(1,541)	415,688
Contributions from parent			(36,704)	(105,261)
Proceeds from borrowings			(481,300)	0
Repayments of borrowings			441,190
Debt issue costs				0
Dividends paid			49,000	177,400
Excess tax benefit (deficit) from share-based compensation				0
Proceeds from exercise of share options				0
Net cash provided by (used in) financing activities			(29,355)	487,827
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