Dispositions (Details Textual) (USD $)	3 Months Ended			1 Months Ended	3 Months Ended	1 Months Ended	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011 Liftboat	Dec. 31, 2011	Mar. 31, 2012 Marine [Member] Liftboat	Mar. 31, 2012 Marine [Member]	Feb. 29, 2012 DB Superior Pride [Member]	Mar. 31, 2012 DB Superior Pride [Member]
Dispositions (Additional Textual) [Abstract]
Pre-tax gain loss after sale		$ 2,700,000					$ 3,100,000
Agreement to sell number of liftboats				18
Outstanding guaranteed long-term financing					12,500,000
Carrying value of goodwill			9,740,000			9,700,000
Make whole premiums associated with early extinguishment of disposal group debt					4,000,000
Wrote off amount of unamortized loans costs.	700,000				700,000
Cash proceeds from sale of businesses	185,912,000	5,762,000		141,400,000		44,500,000
Write off long lived assets	10,000,000				46,100,000
Dispositions (Textual) [Abstract]
Numbers of liftboats sold		3
Loss on disposition	56,100,000
Disposition cost	6,500,000
Loss on sale of assets	$ 3,600,000