Commitments And Contingencies (Narrative) (Details) (USD $)	3 Months Ended				1 Months Ended		3 Months Ended	12 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2013 Purchaser [Member]	Mar. 31, 2013 Helix [Member]	Aug. 31, 2012 Helix 534 [Member]	Mar. 31, 2013 Helix 534 [Member]	Mar. 31, 2013 Q5000 [Member]	Dec. 31, 2010 Allowance for Doubtful Accounts [Member]
Long-term Purchase Commitment, Amount							$ 386,500,000
Property and equipment	2,115,321,000	2,051,796,000				147,900,000	142,600,000
Payments to Acquire Property, Plant, and Equipment					85,000,000		115,900,000
Guarantor Obligations, Maximum Exposure, Undiscounted			100,000,000	50,000,000
Trade receivables collected	303,000,000
Valuation Allowances and Reserves, Deductions								4,000,000
Value added tax assessment	$ 28,000,000