Condensed Consolidated Guarantor and Non-Guarantor Financial Information (Schedule of Condensed Consolidating Balance Sheets) (Details) (USD $) In Thousands	Jun. 30, 2011	Dec. 31, 2010	Jun. 30, 2010	Dec. 31, 2009
Cash and cash equivalents	$ 414,189	$ 391,085	$ 270,001	$ 270,673
Accounts receivable, net	212,406	177,293
Unbilled revenue	20,303	49,411
Income taxes receivable	9,059	6,099
Other current assets	101,275	116,966
Total current assets	757,232	740,854
Intercompany	0	0
Property and equipment, net	2,475,310	2,527,080
Equity investments in unconsolidated affiliates	188,772	187,031
Equity investments in affiliates	0	0
Goodwill, net	62,902	62,494
Other assets, net	76,421	74,561
Due from subsidiaries/parent	0	0
Total assets	3,560,637	3,592,020
Accounts payable	148,142	159,381
Accrued liabilities	190,226	198,237
Income taxes payable	0	0
Current maturities of long-term debt	7,759	10,179
Total current liabilities	346,127	367,797
Long-term debt, noncurrent	1,239,893	1,347,753
Deferred income taxes	431,821	413,639
Asset retirement obligations	166,458	170,410
Other long-term liabilities	5,432	5,777
Due to parent	0	0
Total liabilities	2,189,731	2,305,376
Convertible preferred stock	1,000	1,000
Total equity	1,369,906	1,285,644
Total liabilities and shareholders' equity	3,560,637	3,592,020
Helix [Member]
Cash and cash equivalents	387,772	376,434	251,755	258,742
Accounts receivable, net	54,325	61,846
Unbilled revenue	2,219	11,990
Income taxes receivable	63,514	19,334
Other current assets	47,610	63,306
Total current assets	555,440	532,910
Intercompany	1,294	1,906
Property and equipment, net	221,300	217,153
Equity investments in unconsolidated affiliates	0	0
Equity investments in affiliates	1,947,501	1,998,289
Goodwill, net	0	0
Other assets, net	48,499	43,971
Due from subsidiaries/parent	90,965	95,398
Total assets	2,864,999	2,889,627
Accounts payable	41,121	60,308
Accrued liabilities	58,787	58,074
Income taxes payable	0	0
Current maturities of long-term debt	3,000	4,326
Total current liabilities	102,908	122,708
Long-term debt, noncurrent	1,132,136	1,237,587
Deferred income taxes	213,232	185,453
Asset retirement obligations	0	0
Other long-term liabilities	1,335	1,421
Due to parent	0	0
Total liabilities	1,449,611	1,547,169
Convertible preferred stock	1,000	1,000
Total equity	1,414,388	1,341,458
Total liabilities and shareholders' equity	2,864,999	2,889,627
Guarantors [Member]
Cash and cash equivalents	2,413	3,294	5,035	2,522
Accounts receivable, net	106,506	91,659
Unbilled revenue	0	0
Income taxes receivable	0	0
Other current assets	42,191	49,557
Total current assets	151,110	144,510
Intercompany	294,433	263,920
Property and equipment, net	1,554,186	1,605,906
Equity investments in unconsolidated affiliates	0	0
Equity investments in affiliates	28,432	29,899
Goodwill, net	45,107	45,107
Other assets, net	38,119	38,324
Due from subsidiaries/parent	275,900	105,434
Total assets	2,387,287	2,233,100
Accounts payable	82,403	56,107
Accrued liabilities	96,184	107,874
Income taxes payable	84,684	36,678
Current maturities of long-term debt	0	0
Total current liabilities	263,271	200,659
Long-term debt, noncurrent	0	0
Deferred income taxes	126,992	135,101
Asset retirement obligations	166,458	170,410
Other long-term liabilities	3,480	3,691
Due to parent	0	0
Total liabilities	560,201	509,861
Convertible preferred stock	0	0
Total equity	1,827,086	1,723,239
Total liabilities and shareholders' equity	2,387,287	2,233,100
Non-Guarantors [Member]
Cash and cash equivalents	24,004	11,357	13,211	9,409
Accounts receivable, net	51,575	23,788
Unbilled revenue	18,084	37,421
Income taxes receivable	13,075	7,195
Other current assets	12,712	12,889
Total current assets	119,450	92,650
Intercompany	(212,007)	(171,513)
Property and equipment, net	704,756	709,082
Equity investments in unconsolidated affiliates	188,772	187,031
Equity investments in affiliates	0	0
Goodwill, net	17,795	17,387
Other assets, net	19,639	21,900
Due from subsidiaries/parent	0	0
Total assets	838,405	856,537
Accounts payable	24,618	42,966
Accrued liabilities	35,255	32,289
Income taxes payable	0	0
Current maturities of long-term debt	4,759	14,301
Total current liabilities	64,632	89,556
Long-term debt, noncurrent	107,757	110,166
Deferred income taxes	97,650	98,968
Asset retirement obligations	0	0
Other long-term liabilities	617	665
Due to parent	116,451	120,884
Total liabilities	387,107	420,239
Convertible preferred stock	0	0
Total equity	451,298	436,298
Total liabilities and shareholders' equity	838,405	856,537
Consolidating Entries [Member]
Cash and cash equivalents	0	0	0	0
Accounts receivable, net	0	0
Unbilled revenue	0	0
Income taxes receivable	(67,530)	(20,430)
Other current assets	(1,238)	(8,786)
Total current assets	(68,768)	(29,216)
Intercompany	(83,720)	(94,313)
Property and equipment, net	(4,932)	(5,061)
Equity investments in unconsolidated affiliates	0	0
Equity investments in affiliates	(1,975,933)	(2,028,188)
Goodwill, net	0	0
Other assets, net	(29,836)	(29,634)
Due from subsidiaries/parent	(366,865)	(200,832)
Total assets	(2,530,054)	(2,387,244)
Accounts payable	0	0
Accrued liabilities	0	0
Income taxes payable	(84,684)	(36,678)
Current maturities of long-term debt	0	(8,448)
Total current liabilities	(84,684)	(45,126)
Long-term debt, noncurrent	0	0
Deferred income taxes	(6,053)	(5,883)
Asset retirement obligations	0	0
Other long-term liabilities	0	0
Due to parent	(116,451)	(120,884)
Total liabilities	(207,188)	(171,893)
Convertible preferred stock	0	0
Total equity	(2,322,866)	(2,215,351)
Total liabilities and shareholders' equity	$ (2,530,054)	$ (2,387,244)