Basis Of Presentation (Details)	36 Months Ended
	Dec. 31, 2011 Maximum [Member]	Dec. 31, 2011 Minimum [Member]	Jul. 01, 2011 Dredging [Member]	Jul. 01, 2011 Demolition [Member]
Basis Of Presentation [Line Items]
Average equipment-related costs of total costs of contract revenue	25.00%	21.00%
Fair value in excess of carrying value			35.00%	8.00%