Long-Term Debt (Narrative) (Details) (USD $)	1 Months Ended	12 Months Ended						12 Months Ended			12 Months Ended					12 Months Ended					1 Months Ended		12 Months Ended				1 Months Ended	12 Months Ended									1 Months Ended			12 Months Ended
	Jan. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Aug. 31, 2011	Jun. 30, 2011	May 31, 2011	Dec. 31, 2011 Helix Term Loan [Member]	Dec. 31, 2010 Helix Term Loan [Member]	Jul. 31, 2006 Helix Term Loan [Member]	Dec. 31, 2011 Revolving Credit Facility [Member]	Dec. 31, 2010 Revolving Credit Facility [Member]	Dec. 31, 2011 Helix Revolving Loans [Member]	Jun. 30, 2009 Helix Revolving Loans [Member]	Jul. 31, 2006 Helix Revolving Loans [Member]	Dec. 31, 2011 Senior Unsecured Notes [Member]		Dec. 31, 2010 Senior Unsecured Notes [Member]		Dec. 21, 2007 Senior Unsecured Notes [Member]	Dec. 31, 2005 Convertible Senior Notes [Member]	Mar. 31, 2005 Convertible Senior Notes [Member]	Dec. 31, 2011 Convertible Senior Notes [Member]		Dec. 31, 2010 Convertible Senior Notes [Member]		Sep. 30, 2005 MARAD Debt [Member]	Dec. 31, 2011 MARAD Debt [Member]		Dec. 31, 2010 MARAD Debt [Member]		Dec. 31, 2011 Letters Of Credit [Member]	Dec. 31, 2011 Other [Member]	Dec. 31, 2010 Other [Member]	Dec. 31, 2011 Senior Credit Facility [Member]	Dec. 31, 2011 Maximum [Member]	Feb. 28, 2010 Maximum [Member] Helix Term Loan [Member]	Dec. 31, 2011 Maximum [Member] Helix Revolving Loans [Member]	Dec. 31, 2011 Minimum [Member]	Dec. 31, 2011 Minimum [Member] Helix Term Loan [Member]
Debt Instrument [Line Items]
Unsecured letters of credit																																$ 41,400,000	$ 41,400,000
Long-term debt, noncurrent		1,147,444,000	1,347,753,000					276,750,000								474,960,000							290,445,000	[1]				105,289,000
Long-term debt, carrying value		1,164,876,000	1,376,460,000													474,960,000	[2]	550,000,000	[2]			300,000,000	300,000,000	[2],[3]	300,000,000	[2],[3]		110,166,000	[4]	114,811,000	[4]
Debt instrument purchase price percentage of principal amount																101.00%					1000.00%		1000.00%
Long-term debt										835,000,000
Debt instrument interest rate																				9.50%			3.25%				4.93%
Contingent interest																							0.25%
Conversion percentage threshold of the convertible senior notes																							120.00%
Issuance of notes percentage																						100.00%	100.00%
Stated maturity year																January 15, 2016						2025					February 2027
Aggregate amount of debt payment		77,394,000
Premium on senior unsecured notes																2,400,000
Payment on senior unsecured notes		300,000,000
Extinguishment of Notes																75,000,000
Accrued interest paid on notes		800,000
Loss on early extinguishment of Senior Unsecured Notes		2,354,000
Original borrowing capacity						600,000,000	435,000,000								300,000,000
Cash and cash equivalents plus available capacity under Revolving Credit Facility																500,000,000							400,000,000
Leverage ratio		2.00 to 1.00									4.50 to 1.00																								4.00 to 1.00
Margin increase								0.25%																													2.50%			2.00%
Average interest rate								3.80%	2.90%					3.40%
Debt instrument, interest rate terms								one-, three- or six-month LIBOR at our current election plus a 2.00% margin (as amended in February 2010, the margin was increased up to 2.50% depending on current leverage ratios, as defined).			one-, three- or six-month LIBOR rates or on Base Rates at our current election plus an applicable margin as discussed below.  Margins on the Revolving Loans will fluctuate in relation to the consolidated leverage ratio as provided in the Credit Agreement.
Debt instrument proceeds from sale of oil and gas properties percentage		60.00%
Debt instrument proceeds reinvested into collateral percentage		40.00%
Revolving credit facility available		600,000,000									558,600,000
Repayments of Lines of Credit		109,400,000		349,500,000
Investments in subsidiaries permitted by credit agreement, excluding loan party subsidiaries and subsidiaries with pledged equity interests																																				200,000,000			100,000,000
Repurchases and redemptions permitted under credit agreement, common stock, value																																						50,000,000
Interest rate swap	200,000,000				200,000,000
Interest rate swap maximum term in years	two
Convertible Senior Notes, shares of common stock																					15.56		31.12
Effective interest rate																							6.60%
Per share conversion price		$ 38.56																			$ 64.27		$ 32.14
Conversion rate																							103.00%
Convertible Senior Notes are convertible into shares																							13,303,770
Debt percentage guaranteed																												50.00%
Payments of debt issuance costs		9,300,000	2,900,000
Amortization of deferred financing costs		8,910,000	7,703,000	6,693,000												900,000
Deferred financing costs		$ 26,483,000	$ 25,697,000																														$ 26,500,000	$ 25,700,000

[1] Beginning in December 2012, we may at our option repurchase the notes or the holders may require us to repurchase the notes. The notes will increase to the $300 million face amount through accretion of non-cash interest charges through December 2012.

[2] The fair values of these instruments were based on quoted market prices as of December 31, 2011 and 2010. The fair values were estimated using level 1 inputs using the market approach.

[3] Carrying amounts exclude the $9.6 million and $18.5 million of unamortized discount on the Convertible Senior Notes at December 31, 2011 and 2010, respectively.

[4] The fair value of the MARAD debt was determined by a third-party evaluation of the remaining average life and outstanding principal balance of the MARAD indebtedness as compared to other government guaranteed obligations in the market place with similar terms. The fair value of the MARAD debt was estimated using Level 2 fair value inputs using the market approach.