Summary Of Significant Accounting Policies (Narrative) (Details)	1 Months Ended				3 Months Ended				12 Months Ended							36 Months Ended				12 Months Ended					12 Months Ended
	Dec. 31, 2012 USD ($)		Mar. 31, 2011 USD ($)	May 31, 2010 USD ($)	Dec. 31, 2012 USD ($)		Sep. 30, 2012 USD ($)	Jun. 30, 2012 USD ($)	Dec. 31, 2012 USD ($) customer		Dec. 31, 2011 USD ($)		Dec. 31, 2010 USD ($)		Dec. 31, 2009 USD ($)	Dec. 31, 2012 USD ($)		Jan. 31, 2013 USD ($)	Jan. 31, 2013 NOK	Dec. 31, 2012 Express, Caesar And Other Pipelay Equipment [Member] USD ($)	Dec. 31, 2012 Equipment In Australia [Member] USD ($)	Dec. 31, 2011 Equipment In Australia [Member] USD ($)	Dec. 31, 2012 Intrepid Vessel [Member] USD ($)	Dec. 31, 2012 Segment, Discontinued Operations [Member] USD ($)	Dec. 31, 2012 JP Morgan Ventures [Member] Segment, Discontinued Operations [Member]	Dec. 31, 2012 Shell [Member] Segment, Continuing Operations [Member]	Dec. 31, 2011 Shell [Member] Segment, Continuing Operations [Member]	Dec. 31, 2012 Shell [Member] Segment, Discontinued Operations [Member]	Dec. 31, 2011 Shell [Member] Segment, Discontinued Operations [Member]	Dec. 31, 2010 Shell [Member] Segment, Discontinued Operations [Member]	Dec. 31, 2010 BP Plc [Member] Segment, Continuing Operations [Member]	Dec. 31, 2010 Louis Dreyfus Energy Services [Member] Segment, Discontinued Operations [Member]	Dec. 31, 2012 Interest Rate Swaps [Member] USD ($)	Dec. 31, 2012 Foreign Exchange Forward [Member] USD ($)	Dec. 31, 2011 Foreign Exchange Forward [Member] USD ($)	Dec. 31, 2010 Foreign Exchange Forward [Member] USD ($)	Dec. 31, 2012 Convertible Senior Notes 2025 [Member] USD ($)	Dec. 31, 2012 Convertible Senior Notes 2032 [Member] USD ($)	Jan. 31, 2009 Convertible Senior Notes 2025 [Member] USD ($)
Summary Of Significant Accounting Policies [Line Items]
Accruals for capital expenditures									$ 51,100,000		$ 26,100,000		$ 21,900,000
Cost of Property Repairs and Maintenance									38,700,000		32,300,000		29,300,000
Capitalized Computer Software, Gross	18,500,000				18,500,000				18,500,000		18,100,000					18,500,000
Capitalized Computer Software, Amortization									(2,600,000)		(2,600,000)		(2,600,000)
Asset impairment					158,000,000		4,600,000	14,600,000												157,800,000	4,600,000	6,600,000
Sales price																				238,300,000	5,000,000		14,500,000
Gain (Loss) on Sale of Assets and Asset Impairment Charges																							28,100,000
Deposit Liability, Current	50,000,000	[1]			50,000,000	[1]			50,000,000	[1]						50,000,000	[1]			50,000,000
Capitalized interest									(4,893,000)		(1,277,000)		(12,474,000)
Other than temporary loss on equity investments											10,563,000		2,240,000
Goodwill impairment													16,743,000
Goodwill, net	62,935,000				62,935,000				62,935,000		62,215,000		62,494,000	[2]		62,935,000
Intangible asset, gross	1,700,000				1,700,000				1,700,000							1,700,000
Intangible assets with finite lives, net	491,000				491,000				491,000		531,000					491,000
Finite-Lived Intangible Assets, Accumulated Amortization	1,200,000				1,200,000				1,200,000							1,200,000
Amortization of intangible assets									100,000		100,000		100,000
Finite-Lived Intangible Assets, Next Twelve Months	100,000				100,000				100,000							100,000
Finite-Lived Intangible Assets, Amortization Expense, Year Two	100,000				100,000				100,000							100,000
Finite-Lived Intangible Assets, Amortization Expense, Year Three	100,000				100,000				100,000							100,000
Finite-Lived Intangible Assets, Amortization Expense, Year Four	100,000				100,000				100,000							100,000
Deferred dry dock expenses, net	22,704,000	[3]			22,704,000	[3]			22,704,000	[3]	5,381,000	[3]				22,704,000	[3]
Drydock amortization expense									8,600,000		7,600,000		6,900,000
Value of convertible preferred stock	1,000,000			5,000,000
Stock Issued During Period, Shares, Conversion of Convertible Securities	361,402			1,807,011
Preferred Stock, Dividend Rate, Percentage																4.00%
Foreign currency translation gain, net of tax									7,291,000		(1,002,000)		(10,005,000)
Foreign Currency Transaction Gain (Loss), before Tax									(500,000)		(2,100,000)		1,900,000
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, before Tax									(2,661,000)		23,669,000		(23,726,000)																				600,000
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, Net of Tax									6,800,000																								400,000
Derivative Instruments, Loss Recognized in Income																																		400,000	200,000	(2,600,000)
Notional Amount of Interest Rate Cash Flow Hedge Derivatives	200,000,000				200,000,000				200,000,000							200,000,000
Notional Amount of Foreign Currency Derivatives																		104,600,000	591,300,000
Concentration Risk, Percentage																									26.00%	12.00%	10.00%	64.00%	89.00%	67.00%	26.00%	19.00%
Subsea services to customers									70
Unamortized debt discount	31,688,000	[4]			31,688,000	[4]			31,688,000	[4]	9,555,000					31,688,000	[4]																						60,200,000
Gas and oil imbalance																								4,000,000
Gas Balancing Payable, Current																								3,000,000
Remaining ownership interest													1.00%
Remaining shares of Cal Dive common stock, shares			500,000										500,000
Gain (loss) on investment in Cal Dive common stock			800,000								753,000
Proceeds from sale of Cal Dive common stock			3,600,000								3,588,000				418,200,000
Derivative Instruments Not Designated as Hedging Instruments, Asset, at Fair Value	5,946,000				5,946,000				5,946,000		55,000					5,946,000																		100,000
Derivative Instruments Not Designated as Hedging Instruments, Liability, at Fair Value	16,298,000				16,298,000				16,298,000		159,000					16,298,000																			100,000
Convertible debt stock price trigger																																					$ 38.57	$ 32.53
Debt Instrument, Unamortized Discount	$ 31,688,000	[4]			$ 31,688,000	[4]			$ 31,688,000	[4]	$ 9,555,000					$ 31,688,000	[4]																						$ 60,200,000
Debt Instrument, Convertible, Remaining Discount Amortization Period									6 years

[1] Reflects the cash deposit we received in association with the expected sales of our two remaining pipelay vessels, the Express and the Caesar, and other related pipelay equipment (Note 2), which is refundable in very limited circumstances. The sales of these vessels are scheduled to close and fund in two stages in 2013 following the completion of each vessel’s existing backlog of work.

[2] In 2010, we fully impaired $16.7 million of goodwill associated with our Australian well intervention subsidiary (“WOSEA”) (see below).

[3] The increase subsequent to December 31, 2011 reflects the costs associated with the regulatory dry docks for our Q4000, Seawell and Well Enhancer vessels during 2012.

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