Summary Of Significant Accounting Policies (Fair Value Of Long Term Debt) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended											1 Months Ended
	Dec. 31, 2012		Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Term Loan [Member]		Dec. 31, 2011 Term Loan [Member]		Feb. 19, 2013 Revolving Credit Facility [Member]	Dec. 31, 2012 Revolving Credit Facility [Member]		Feb. 28, 2013 Convertible Senior Notes 2025 [Member]	Dec. 31, 2012 Convertible Senior Notes 2025 [Member]		Dec. 31, 2011 Convertible Senior Notes 2025 [Member]		Mar. 31, 2005 Convertible Senior Notes 2025 [Member]	Dec. 31, 2012 Senior Unsecured Notes [Member]	Dec. 31, 2011 Senior Unsecured Notes [Member]	Dec. 31, 2012 MARAD Debt [Member]		Dec. 31, 2011 MARAD Debt [Member]		Dec. 31, 2012 Loan Notes [Member]	Dec. 31, 2011 Loan Notes [Member]	Dec. 31, 2012 Convertible Senior Notes 2032 [Member]		Mar. 31, 2012 Convertible Senior Notes 2032 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, Carrying Value					$ 367,181	[1]	$ 279,750	[1]	$ 78,100	$ 100,000	[1]		$ 3,487	[2]	$ 300,000	[2]	$ 300,000	$ 274,960	$ 474,960	$ 105,288	[3]	$ 110,166	[3]	$ 1,050,916	$ 1,164,876	$ 200,000	[4]	$ 200,000
Long-term debt, Fair Value					368,295	[1]	279,750	[1]		100,000	[1]		3,487	[2]	300,543	[2]		283,209	501,083	123,187	[3]	124,488	[3]	1,117,498	1,205,864	239,320	[4]
Unamortized debt discount	31,688	[5]	9,555												9,600											31,688	[5],[6]	35,400
Repayment of Helix Term Notes	$ 12,569		$ 130,691	$ 4,326								$ 3,500	$ 154,300

[1] In February 2013, we repaid $293.9 million of our Term Loans and $24.5 million under our Revolving Credit Facility with the after-tax proceeds from the sale of ERT.

[2] Carrying value excludes the related unamortized debt discount of $9.6 million at December 31, 2011.

[3] 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.

[4] Carrying value excludes the related unamortized debt discount of $31.7 million at December 31, 2012.

[5] 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.

[6] Beginning in March 2018, 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 2032.