Commitments And Contingencies (Details)	0 Months Ended	1 Months Ended	3 Months Ended				9 Months Ended	12 Months Ended					12 Months Ended
	Sep. 30, 2010 USD ($)	Apr. 30, 2010 AUD	Mar. 31, 2011 USD ($)	Jun. 30, 2010 USD ($)	Mar. 31, 2010 USD ($)	Mar. 31, 2009 USD ($)	Sep. 30, 2010 USD ($)	Dec. 31, 2011 USD ($)	Dec. 31, 2010 USD ($)	Dec. 31, 2009 USD ($)	Dec. 31, 2008 USD ($)	Mar. 31, 2009 AUD	Dec. 31, 2011 Q4000, Helix Producer I And Well Enhancer [Member] USD ($)	Dec. 31, 2011 Intrepid, Seawell And Express [Member] USD ($)	Dec. 31, 2011 Caesar [Member] USD ($)	Dec. 31, 2011 P&I And General Liability [Member] USD ($)	Dec. 31, 2011 Maritime Employers Liability [Member] USD ($)
Loss Contingencies [Line Items]
Future minimum rentals								$ 54,400,000
Future minimum rent due in 2012								42,800,000
Future minimum rent due in 2013								7,600,000
Future minimum rent due in 2014								1,800,000
Future minimum rent due in 2015								1,200,000
Future minimum rent due in 2016								400,000
Future minimum rent thereafter								600,000
Rental expense								62,200,000	66,200,000	89,900,000
Insurance deductibles													1,000,000	500,000	375,000	100,000	100,000
Insurance annual aggregate deductible								1,250,000									1,000,000
Insurance liability limits								500,000,000
Self-insured retention for employees								250,000
Liability for damages												32,000,000
Approximate actual damages						12,000,000
Damage claims paid		15,000,000
Settlement of claims					17,500,000
Payments for litigation settlements					13,800,000
Remaining trade receivable write off					3,700,000				3,700,000
Trade receivables collected								303,000,000
Trade receivable allowance	4,000,000
Value added tax assessment								28,000,000
Estimated loss under the contract										15,800,000	9,000,000
Settlement of obligation under the contract										12,700,000
Previously accrued loss			200,000				12,000,000		30,000,000	3,700,000
Loss on contract termination				$ 5,500,000							$ 7,200,000