Condensed Consolidated Guarantor And Non-Guarantor Financial Information (Schedule Of Condensed Consolidating Balance Sheets) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011	Sep. 30, 2011	Dec. 31, 2010
Cash and cash equivalents	$ 583,794	$ 546,465	$ 375,355	$ 391,085
Accounts receivable, net	198,046	238,781
Unbilled revenue	49,599	37,375
Income taxes receivable	10,135
Other current assets	121,762	121,621
Total current assets	963,336	944,242
Property and equipment, net	2,431,827	2,331,327
Equity investments in unconsolidated affiliates	169,318	175,656
Goodwill, net	62,769	62,215
Other assets, net	84,707	68,907
Total assets	3,711,957	3,582,347
Accounts payable	164,110	147,043
Accrued liabilities	196,289	239,963
Income taxes payable		1,293
Current maturities of long-term debt	13,120	7,877
Total current liabilities	373,519	396,176
Long-term debt	1,159,958	1,147,444
Deferred tax liabilities	455,266	417,610
Asset retirement obligations	136,293	161,208
Other long-term liabilities	8,336	9,368
Total liabilities	2,133,372	2,131,806
Convertible preferred stock	1,000	1,000
Total equity	1,577,585	1,449,541
Total liabilities and shareholders' equity	3,711,957	3,582,347
Helix [Member]
Cash and cash equivalents	513,938	495,484	335,063	376,434
Accounts receivable, net	68,808	79,290
Unbilled revenue	12,633	10,530
Income taxes receivable	25,557	80,388
Other current assets	68,422	68,627
Total current assets	689,358	734,319
Intercompany	(14,878)	(147,187)
Property and equipment, net	219,244	230,946
Equity investments in affiliates	2,015,444	1,952,392
Other assets, net	53,657	53,425
Due from subsidiaries/parent	40,754	64,655
Total assets	3,003,579	2,888,550
Accounts payable	41,754	39,280
Accrued liabilities	60,873	115,921
Current maturities of long-term debt	8,000	3,000
Total current liabilities	110,627	158,201
Long-term debt	1,059,790	1,042,155
Deferred tax liabilities	239,026	231,255
Other long-term liabilities	1,548	4,150
Total liabilities	1,410,991	1,435,761
Convertible preferred stock	1,000	1,000
Total equity	1,591,588	1,451,789
Total liabilities and shareholders' equity	3,003,579	2,888,550
Guarantors [Member]
Cash and cash equivalents	8,367	2,434	1,060	3,294
Accounts receivable, net	86,348	117,767
Unbilled revenue	213	155
Other current assets	33,325	48,661
Total current assets	128,253	169,017
Intercompany	226,890	315,821
Property and equipment, net	1,446,593	1,422,326
Equity investments in affiliates	56,263	37,239
Goodwill, net	45,107	45,107
Other assets, net	33,132	36,453
Due from subsidiaries/parent	598,407	430,496
Total assets	2,534,645	2,456,459
Accounts payable	88,304	82,750
Accrued liabilities	114,528	97,692
Income taxes payable	29,588	97,692
Total current liabilities	232,420	278,134
Deferred tax liabilities	115,150	88,625
Asset retirement obligations	136,293	161,208
Other long-term liabilities	6,281	4,647
Total liabilities	490,144	532,614
Total equity	2,044,501	1,923,845
Total liabilities and shareholders' equity	2,534,645	2,456,459
Non-Guarantors [Member]
Cash and cash equivalents	61,489	48,547	39,232	11,357
Accounts receivable, net	42,890	41,724
Unbilled revenue	36,753	26,690
Other current assets	20,013	10,159
Total current assets	161,145	127,120
Intercompany	(130,679)	(102,826)
Property and equipment, net	770,651	682,899
Equity investments in unconsolidated affiliates	169,318	175,656
Goodwill, net	17,662	17,108
Other assets, net	35,414	16,809
Total assets	1,023,511	916,766
Accounts payable	34,052	25,013
Accrued liabilities	20,888	26,350
Income taxes payable	1,736	217
Current maturities of long-term debt	5,120	10,377
Total current liabilities	61,796	61,957
Long-term debt	100,168	105,289
Deferred tax liabilities	106,582	103,552
Other long-term liabilities	507	571
Due to parent	74,384	98,285
Total liabilities	343,437	369,654
Total equity	680,074	547,112
Total liabilities and shareholders' equity	1,023,511	916,766
Consolidating Entries [Member]
Income taxes receivable	(15,422)	(80,388)
Other current assets	2	(5,826)
Total current assets	(15,420)	(86,214)
Intercompany	(81,333)	(65,808)
Property and equipment, net	(4,661)	(4,844)
Equity investments in affiliates	(2,071,707)	(1,989,631)
Other assets, net	(37,496)	(37,780)
Due from subsidiaries/parent	(639,161)	(495,151)
Total assets	(2,849,778)	(2,679,428)
Income taxes payable	(31,324)	(96,616)
Current maturities of long-term debt		(5,500)
Total current liabilities	(31,324)	(102,116)
Deferred tax liabilities	(5,492)	(5,822)
Due to parent	(74,384)	(98,285)
Total liabilities	(111,200)	(206,223)
Total equity	(2,738,578)	(2,473,205)
Total liabilities and shareholders' equity	$ (2,849,778)	$ (2,679,428)