Long-Term Debt (Narrative) (Details) (USD $)	3 Months Ended					3 Months Ended										1 Months Ended		3 Months Ended		1 Months Ended	3 Months Ended				3 Months Ended
	Mar. 31, 2012		Mar. 31, 2011	Mar. 06, 2012	Dec. 31, 2011	Mar. 31, 2012 Convertible Senior Notes 2032 [Member]		Mar. 31, 2012 Helix Term Loan [Member]		Feb. 21, 2012 Helix Term Loan [Member]	Mar. 31, 2011 Helix Term Loan [Member]	Jul. 31, 2006 Helix Term Loan [Member]	Mar. 31, 2012 Revolving Credit Facility [Member]	Jul. 31, 2006 Revolving Credit Facility [Member]	Mar. 31, 2012 Helix Revolving Loans [Member]	Mar. 31, 2012 Senior Unsecured Notes [Member]	Dec. 31, 2007 Senior Unsecured Notes [Member]	Mar. 31, 2012 Senior Unsecured Notes [Member]	Dec. 31, 2011 Senior Unsecured Notes [Member]	Mar. 31, 2005 Convertible Senior Notes 2025 [Member]	Mar. 31, 2012 Convertible Senior Notes 2025 [Member]		Mar. 31, 2011 Convertible Senior Notes 2025 [Member]	Mar. 31, 2010 Convertible Senior Notes 2025 [Member]	Mar. 31, 2012 MARAD Debt [Member]		Sep. 30, 2005 MARAD Debt [Member]	Mar. 31, 2012 Letters Of Credit [Member]	Mar. 31, 2012 Helix [Member]	Dec. 31, 2011 Helix [Member]	Mar. 31, 2012 Minimum [Member] Helix Term Loan [Member]	Mar. 31, 2012 Minimum [Member] Helix Revolving Loans [Member]	Mar. 31, 2012 Maximum [Member] Helix Term Loan [Member]	Mar. 31, 2012 Maximum [Member] Helix Revolving Loans [Member]
DebtInstrumentConvertibleConversionPremiumPercentage	35.00%
Issuance of notes percentage						100.00%
Convertible Senior Notes, shares of common stock						39.9752
Unsecured letters of credit	$ 46,200,000																											$ 46,200,000
Long-term debt, noncurrent	1,167,486,000				1,147,444,000	164,625,000	[1]	371,000,000	[2]						100,000,000	274,960,000		274,960,000			154,142,000	[3]			102,759,000				1,064,726,000	1,042,155,000
Long-term debt, Carrying Value						200,000,000							100,000,000			274,960,000		274,960,000	475,000,000	300,000,000					107,756,000	[4]
Long-term debt																	550,000,000				157,800,000
Debt instrument interest rate						3.25%											9.50%			3.25%							4.93%
Stated maturity Year																	2016
Aggregate amount of debt payment	209,500,000																	213,500,000
Payment on senior notes																(200,000,000)					145,100,000
Premium on debt extinguishment																		9,500,000			1,800,000
Accrued interest on notes	32,554,000		32,093,000															4,000,000			1,100,000
Accelerated amortization of debt discount	1,611,000		2,207,000																		3,500,000
Loss on early extinguishment of debt	17,127,000																	11,500,000			5,600,000
Original borrowing capacity													600,000,000	300,000,000
Margin range																															2.25%	1.50%	3.50%	3.50%
Revolving credit facility, outstanding												835,000,000	100,000,000
Average interest rate								4.00%			3.00%		3.00%
Revolving credit facility available										100,000,000			453,800,000
Credit facility, annual amortization of principal balance										5,000,000
Interest rate swap	200,000,000
Debt instrument issued percentage																				100.00%
Effective interest rate						6.90%															6.60%
Per share conversion price						$ 25.02																	$ 32.14	$ 32.14
Deferred financing costs, net	28,081,000				26,483,000
Amortization of deferred financing costs	2,355,000		1,981,000															2,000,000			300,000
Debt Instrument, Repurchase Amount																					142,200,000
Proceeds from Issuance of Debt						195,000,000
Debt percentage guaranteed																									50.00%
Notional Amount of Interest Rate Cash Flow Hedge Derivatives	200,000,000
Closing price per share				$ 18.53
Debt Instrument, Unamortized Discount	$ 39,063,000	[5]				$ 35,375,000	[1],[5]														$ 3,688,000	[3],[5]

[1] Beginning in March 2018, the holders of these Convertible Senior Notes may require us to repurchase these notes or we may at our election elect to repurchase the notes. These notes will mature in March 2032.

[2] Amounts reflect both our Term Loan and new Term Loan A.

[3] Beginning in December 2012, the holders of these Convertible Senior Notes may require us to repurchase these notes or we may at our own option elect to repurchase notes. These notes will mature in March 2025.

[4] The estimated fair value of all debt, other than the MARAD debt, was determined using Level 1 inputs using the market approach. The fair value of the MARAD debt was determined using a third party evaluation of the remaining average life and outstanding principal balance of the MARAD indebtedness as compared to other governmental obligations in the marketplace with similar terms. The fair value of the MARAD Debt was estimated using Level 2 fair value inputs using the market approach.

[5] The notes will increase to their principal amount through accretion of non-cash interest charges through December 2012 for the Convertible Senior Notes due 2025 and March 2018 for the Convertible Senior Notes due 2032.