Business Acquisitions (Narrative) (Details) (USD $)	6 Months Ended					6 Months Ended					12 Months Ended
	Jun. 30, 2012		Jun. 30, 2012 Wind Farm Utility Vessel [Member] equipment	Jun. 25, 2012 Pantagro Acquisition [Member] [Member]	Mar. 30, 2012 Superior Energy Services, LLC [Member]	Jun. 30, 2012 Superior Energy Services, LLC [Member] Liftboats [Member]	Feb. 01, 2012 ICP Acquisition [Member]	Mar. 31, 2012 Lewis & Clark Acquisition [Member]	Dec. 31, 2011 Lewis & Clark Acquisition [Member]	Dec. 22, 2011 Windcat Acquisition [Member]	Dec. 31, 2011 Windcat Acquisition [Member] Wind Farm Utility Vessel [Member]	Dec. 21, 2011 Naviera Acquisition [Member]	Jul. 29, 2011 Soylutions Acquisition [Member]
Business Acquisition [Line Items]
Number Of Equipments Delivered			1			18					29
Purchase price of acquisition	$ 148,084,000	[1]		$ 400,000	$ 142,500,000		$ 9,100,000		$ 29,600,000	$ 21,500,000		$ 1,900,000	$ 11,900,000
Business Acquisition, Cost of Acquired Entity, Cash Paid				200,000
Business Acquisition, Cost of Acquired Entity, Liabilities Incurred				200,000
Equity Method Investment, Ownership Percentage				95.00%			70.00%			75.00%
Business acquisition goodwill								1,600,000				1,000,000
Controlling interest obtained												70.00%	100.00%
Cash acquired from acquisition	$ 3,700,000

[1] Purchase price is net of cash acquired of $3.7 million.