Long-Term Contracts (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2012 item	Dec. 31, 2011
Business Acquisition [Line Items]
Contractual arrangements fixed sum	$ 750
Number of downed oil and gas platforms and related well facilities decommissioned	7
Costs and estimated earnings in excess of billings included in other current assets	10.7	133.4
Shell Offshore Inc. [Member]
Business Acquisition [Line Items]
Percentage of ownership acquired by Wild Well in Shell Offshore Inc.'s Gulf of Mexico Bullwinkle platform	100.00%
Wild Well [Member]
Business Acquisition [Line Items]
Performance bonds required to be obtained by Wild Well	50.0
Amounts to be funded in Escrow account by Wild Well	50.0
Escrowed cash included in intangible and other long-term assets, net	50.4	50.2
Costs and estimated earnings in excess of billings included in other current assets		$ 129.7