Goodwill and Intangible Assets (Schedule of the Effect of the Reorganization on Goodwill) (Details) (USD $)	3 Months Ended	9 Months Ended
	Jun. 30, 2014	Sep. 30, 2014
Goodwill
Balance at beginning of period		$ 577,756,000
Goodwill recorded in connection with an acquisition		7,250,000
Balance at end of period		585,006,000
Acquisition related adjustments	7,300,000
Civil [Member]
Goodwill
Balance at beginning of period		374,153,000
Goodwill redistribution in connection with reorganization		41,205,000
Balance at end of period		415,358,000
Building [Member]
Goodwill
Balance at beginning of period		10,502,000
Goodwill redistribution in connection with reorganization		2,953,000
Balance at end of period		13,455,000
Specialty Contractors [Member]
Goodwill
Balance at beginning of period		148,943,000
Goodwill recorded in connection with an acquisition		7,250,000
Balance at end of period		156,193,000
Management Services [Member]
Goodwill
Balance at beginning of period		44,158,000
Goodwill redistribution in connection with reorganization		(44,158,000)
Goodwill recorded in connection with an acquisition
Balance at end of period