Condensed Consolidated Guarantor And Non-Guarantor Financial Information (Schedule Of Condensed Consolidating Balance Sheets) (Details) (USD $) In Thousands	Sep. 30, 2011	Dec. 31, 2010	Sep. 30, 2010	Dec. 31, 2009
Cash and cash equivalents	$ 375,355	$ 391,085	$ 325,480	$ 270,673
Accounts receivable, net	221,162	177,293
Unbilled revenue	28,874	49,411
Income taxes receivable		6,099
Other current assets	123,236	116,966
Total current assets	748,627	740,854
Property and equipment, net	2,473,753	2,527,080
Equity investments in unconsolidated affiliates	186,423	187,031
Goodwill, net	62,344	62,494
Other assets, net	80,862	74,561
Total assets	3,552,009	3,592,020
Accounts payable	145,112	159,381
Accrued liabilities	159,676	198,237
Income taxes payable	3,856
Current maturities of long-term debt	7,877	10,179
Total current liabilities	316,521	367,797
Long-term debt	1,163,914	1,347,753
Deferred income taxes	441,520	413,639
Asset retirement obligations	169,429	170,410
Other long-term liabilities	4,844	5,777
Total liabilities	2,096,228	2,305,376
Convertible preferred stock	1,000	1,000
Total equity	1,454,781	1,285,644
Total liabilities and shareholders' equity	3,552,009	3,592,020
Helix [Member]
Cash and cash equivalents	335,063	376,434	303,787	258,742
Accounts receivable, net	76,595	61,846
Unbilled revenue	13,235	11,990
Income taxes receivable	39,013	19,334
Other current assets	60,957	63,306
Total current assets	524,863	532,910
Intercompany	(16,546)	1,906
Property and equipment, net	219,450	217,153
Equity investments in affiliates	1,989,756	1,998,289
Other assets, net	46,672	43,971
Due from subsidiaries/parent	82,918	95,398
Total assets	2,847,113	2,889,627
Accounts payable	42,650	60,308
Accrued liabilities	50,000	58,074
Current maturities of long-term debt	3,000	4,326
Total current liabilities	95,650	122,708
Long-term debt	1,058,626	1,237,587
Deferred income taxes	227,047	185,453
Other long-term liabilities	1,351	1,421
Total liabilities	1,382,674	1,547,169
Convertible preferred stock	1,000	1,000
Total equity	1,463,439	1,341,458
Total liabilities and shareholders' equity	2,847,113	2,889,627
Guarantors [Member]
Cash and cash equivalents	1,060	3,294	3,853	2,522
Accounts receivable, net	92,881	91,659
Unbilled revenue	18
Other current assets	49,739	49,557
Total current assets	143,698	144,510
Intercompany	276,281	263,920
Property and equipment, net	1,552,025	1,605,906
Equity investments in affiliates	35,708	29,899
Goodwill, net	45,107	45,107
Other assets, net	45,977	38,324
Due from subsidiaries/parent	331,591	105,434
Total assets	2,430,387	2,233,100
Accounts payable	74,003	56,107
Accrued liabilities	81,412	107,874
Income taxes payable	62,870	36,678
Total current liabilities	218,285	200,659
Deferred income taxes	120,838	135,101
Asset retirement obligations	169,429	170,410
Other long-term liabilities	2,899	3,691
Total liabilities	511,451	509,861
Total equity	1,918,936	1,723,239
Total liabilities and shareholders' equity	2,430,387	2,233,100
Non-Guarantors [Member]
Cash and cash equivalents	39,232	11,357	17,840	9,409
Accounts receivable, net	51,686	23,788
Unbilled revenue	15,621	37,421
Income taxes receivable	2,691	7,195
Other current assets	13,832	12,889
Total current assets	123,062	92,650
Intercompany	(210,909)	(171,513)
Property and equipment, net	707,165	709,082
Equity investments in unconsolidated affiliates	186,423	187,031
Goodwill, net	17,237	17,387
Other assets, net	17,625	21,900
Total assets	840,603	856,537
Accounts payable	28,459	42,966
Accrued liabilities	28,264	32,289
Current maturities of long-term debt	4,877	14,301
Total current liabilities	61,600	89,556
Long-term debt	105,288	110,166
Deferred income taxes	99,249	98,968
Other long-term liabilities	594	665
Due to parent	108,403	120,884
Total liabilities	375,134	420,239
Total equity	465,469	436,298
Total liabilities and shareholders' equity	840,603	856,537
Consolidating Entries [Member]
Income taxes receivable	(41,704)	(20,430)
Other current assets	(1,292)	(8,786)
Total current assets	(42,996)	(29,216)
Intercompany	(48,826)	(94,313)
Property and equipment, net	(4,887)	(5,061)
Equity investments in affiliates	(2,025,464)	(2,028,188)
Other assets, net	(29,412)	(29,634)
Due from subsidiaries/parent	(414,509)	(200,832)
Total assets	(2,566,094)	(2,387,244)
Income taxes payable	(59,014)	(36,678)
Current maturities of long-term debt		(8,448)
Total current liabilities	(59,014)	(45,126)
Deferred income taxes	(5,614)	(5,883)
Due to parent	(108,403)	(120,884)
Total liabilities	(173,031)	(171,893)
Total equity	(2,393,063)	(2,215,351)
Total liabilities and shareholders' equity	$ (2,566,094)	$ (2,387,244)