Business Segment Information (Intercompany Segment Assets) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Assets	$ 3,688,805	$ 3,582,347
Helix [Member]
Assets	3,007,188	2,888,550
Contracting Services [Member]
Assets	2,176,796	2,006,065
Production Facilities [Member]
Assets	534,714	534,776
Oil and Gas [Member]
Assets	$ 977,295	$ 1,041,506