Acquisitions (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2014 Effective Companies [Member]	Apr. 01, 2014 Effective Companies [Member]	Sep. 30, 2014 Prospero [Member]
Business Acquisition [Line Items]
Cash purchase price				$ 9,000
Fair value of contingent consideration				5,345
Estimated working capital adjustment				(91)
Total purchase price				14,254
Cash				334
Accounts receivable				1,283
Prepaid expenses and other assets				496
Property and equipment				80
Amortizable intangible assets				1,613
Goodwill	127,514	116,987		12,338
Total assets acquired				16,144
Accounts payable, accrued expenses and other liabilities				582
Billings in excess of costs and estimated earnings on uncompleted contracts				940
Deferred tax liability				368
Total liabilities assumed				1,890
Net assets acquired				14,254
Maximum contingent consideration due in 2014	0				0
Maximum contingent consideration due in 2015	4,753		2,960		1,793
Maximum contingent consideration due in 2016	2,960		2,960		0
Maximum contingent consideration due Total	7,713		5,920		1,793
Original range of potential undiscounted payments minimum			0		0
Original range of potential undiscounted payments maximum			$ 5,921		$ 4,482