Dispositions and Discontinued Operations Information Related to the Sale of Several of the Company's Assets (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended			3 Months Ended	9 Months Ended		0 Months Ended	9 Months Ended	1 Months Ended		9 Months Ended	1 Months Ended	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2012 Hercules 2501 Domestic Offshore	Sep. 30, 2012 Platform Rig 3 International Offshore	Sep. 30, 2012 Platform Rig 3 International Offshore	Sep. 30, 2012 Hercules 101 Domestic Offshore	Jul. 02, 2013 Domestic Liftboats Various	Sep. 30, 2013 Domestic Liftboats Various	Jul. 31, 2013 Inland Various barge	May 31, 2013 Inland Various	Sep. 30, 2013 Inland Various	Aug. 31, 2013 Inland Hercules 27	Sep. 30, 2013 Inland Hercules 27	Sep. 30, 2012 Inland Hercules 29	Sep. 30, 2013 Discontinued Operations Domestic Liftboats Various	Sep. 30, 2013 Discontinued Operations Inland Various	Sep. 30, 2013 Discontinued Operations Inland Hercules 27	Sep. 30, 2012 Discontinued Operations Inland Hercules 29
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Barges Sold									11
Period Of Sale			2012-06		2012-08	2012-09		2013-07			2013-07		2013-08	2012-07
Proceeds	$ 103,927	$ 44,616	$ 7,000			$ 1,200								$ 900
Gain/(Loss)				18,350	18,350
Gain(Loss)	4,834	24,585	5,465			0												770
Proceeds					35,516		54,447	54,447		45,000	44,331	5,149	5,149
Gain/(Loss)															$ 0	$ 0	$ 4,834