Commitments And Contingencies (Narrative) (Details) (USD $)	3 Months Ended	9 Months Ended	12 Months Ended					12 Months Ended		1 Months Ended	12 Months Ended
	Mar. 31, 2011	Sep. 30, 2010	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Purchaser [Member]	Dec. 31, 2012 Helix [Member]	Dec. 31, 2012 Annual Aggregate [Member]	Dec. 31, 2012 Q4000 Helix Producer I And Well Enhancer [Member]	Aug. 31, 2012 Helix 534 [Member]	Dec. 31, 2012 Helix 534 [Member]	Dec. 31, 2012 Q5000 [Member]	Dec. 31, 2012 Seawell, Express And H534 [Member]	Dec. 31, 2012 Caesar Vessel [Member]	Dec. 31, 2012 General Liability [Member] Per Occurance [Member]	Dec. 31, 2012 Maritime Employers Liability [Member] Per Occurance [Member]	Dec. 31, 2012 Maritime Employers Liability [Member] Annual Aggregate [Member]	Dec. 31, 2010 Allowance for Doubtful Accounts [Member]	Dec. 31, 2012 Allowance for Doubtful Accounts [Member] Helix [Member]		Dec. 31, 2011 Allowance for Doubtful Accounts [Member] Helix [Member]		Dec. 31, 2010 Allowance for Doubtful Accounts [Member] Helix [Member]		Dec. 31, 2012 Valuation Allowance of Deferred Tax Assets [Member] Helix [Member]		Dec. 31, 2011 Valuation Allowance of Deferred Tax Assets [Member] Helix [Member]		Dec. 31, 2010 Valuation Allowance of Deferred Tax Assets [Member] Helix [Member]
Long-term Purchase Commitment, Amount												$ 386,500,000
Payments to Acquire Property, Plant, and Equipment										85,000,000	113,500,000	115,900,000
Property and equipment			2,051,796,000	1,815,012,000								139,600,000
Self-insured retention for employees			250,000
Insurance liability limits			500,000,000
Insurance Deductibles								5,000,000	1,000,000				500,000	750,000	100,000	100,000	1,000,000
Remaining trade receivable write off																		4,000,000
Trade receivables collected			303,000,000
Value added tax assessment			28,000,000
Operating Leases, Rent Expense, Net			85,000,000	62,200,000	66,200,000
Loss Contingency, Loss in Period	200,000	12,000,000			30,000,000
Valuation Allowances and Reserves, Deductions																		4,000,000	1,257,000	[1]	61,000	[2]	4,108,000	[3]	2,081,000	[1]	5,813,000	[2]	8,497,000	[3]
Guarantor Obligations, Maximum Exposure, Undiscounted						$ 100,000,000	$ 50,000,000

[1] The increase in valuation allowance includes $2.0 million related to our WOSEA operations and $0.1 million to our oil and gas operations in the United Kingdom. WOSEA has a full valuation allowance against its deferred tax asset balance.

[2] The increase in valuation allowance includes $4.9 million related to our WOSEA and $0.9 million to our oil and gas operations in the United Kingdom.

[3] Amounts include a $4.0 million bad debt allowance related to a large international construction contract and a $7.3 million increase in valuation allowance related to our WOSEA operations with the remaining allowance being related to our acquisition of the remaining 50% of the Camelot field in the United Kingdom.