Selected Balance Sheet Accounts (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Schedule of Equity Method Investments [Line Items]
Inventory for remotely operated vehicles	$ 188,197	$ 174,612
Other inventory, primarily raw materials	257,820	156,668
Total	446,017	331,280
Investments in unconsolidated affiliates	38,669	42,619
Medusa Spar LLC Investment [Member]
Schedule of Equity Method Investments [Line Items]
Investments in unconsolidated affiliates	38,581	42,540
Other Equity Method Investees [Member]
Schedule of Equity Method Investments [Line Items]
Investments in unconsolidated affiliates	$ 88	$ 79