Acquisitions (Details) (USD $) In Thousands, unless otherwise specified	0 Months Ended		1 Months Ended	12 Months Ended	0 Months Ended	1 Months Ended	0 Months Ended	12 Months Ended	0 Months Ended
	Apr. 01, 2014	May 31, 2013	May 31, 2013	Dec. 31, 2014	Jun. 12, 2013	Jun. 30, 2013	May 01, 2012	Dec. 31, 2013	Jun. 29, 2012	Sep. 17, 2012	Oct. 01, 2012	Dec. 31, 2012
Business Acquisition [Line Items]
Potential additional consideration for acquisitions				$ 7,388
Purchase price allocation:
Goodwill				125,757				116,987				102,821
Effective Companies [Member]
Business Acquisition [Line Items]
Potential additional consideration for acquisitions				5,668
Cash purchase price	9,000
Fair value of contingent consideration	5,345
Working capital adjustment	4
Total purchase price	14,349
Purchase price allocation:
Cash	334
Accounts receivable	1,378
Other assets	496
Property, plant and equipment	80
Amortizable intangible assets	1,613
Goodwill	12,556
Total assets	16,457
Accounts payable and accrued expenses	582
Billings in excess of costs and estimated earnings on uncompleted contracts	940
Deferred tax liability	586
Total liabilities	2,108
Net assets acquired	14,349
Prospero [Member]
Business Acquisition [Line Items]
Potential additional consideration for acquisitions				1,720
Acquisition date				May 31, 2013
Cash purchase price		7,046	7,028
Fair value of contingent consideration			3,670
Total purchase price			10,698
Purchase price allocation:
Cash		0	0
Accounts receivable		0	0
Other assets		7	7
Property, plant and equipment		51	51
Intangible assets		2,801	2,801
Goodwill		8,112	8,112
Total assets		10,971	10,971
Accounts payable and accrued expenses		40	40
Billings in excess of costs and estimated earnings on uncompleted contracts		233	233
Deferred tax liability		0	0
Total liabilities		273	273
Net assets acquired		10,698	10,698
Lorien [Member]
Business Acquisition [Line Items]
Acquisition date				Jun. 12, 2013
Cash purchase price					6,734	6,734
Fair value of contingent consideration						573
Total purchase price						7,307
Purchase price allocation:
Cash					23
Accounts receivable					1,856
Other assets					1,553
Property, plant and equipment					116
Intangible assets					1,715
Goodwill					5,494
Total assets					10,757
Accounts payable and accrued expenses					1,975
Billings in excess of costs and estimated earnings on uncompleted contracts					1,132
Deferred tax liability					343
Total liabilities					3,450
Net assets acquired					7,307
Information Horizons [Member]
Business Acquisition [Line Items]
Acquisition date								May 01, 2012
Cash purchase price							531
Fair value of contingent consideration							0
Total purchase price							531
Purchase price allocation:
Cash							0
Accounts receivable							0
Other assets							0
Property, plant and equipment							26
Intangible assets							505
Goodwill							0
Total assets							531
Accounts payable and accrued expenses							0
Billings in excess of costs and estimated earnings on uncompleted contracts							0
Deferred tax liability							0
Total liabilities							0
Net assets acquired							531
Asentus [Member]
Business Acquisition [Line Items]
Acquisition date								Jun. 29, 2012
Cash purchase price									1,417
Fair value of contingent consideration									765
Total purchase price									2,182
Purchase price allocation:
Cash									396
Accounts receivable									1,970
Other assets									411
Property, plant and equipment									46
Intangible assets									443
Goodwill									1,957
Total assets									5,223
Accounts payable and accrued expenses									2,708
Billings in excess of costs and estimated earnings on uncompleted contracts									247
Deferred tax liability									86
Total liabilities									3,041
Net assets acquired									2,182
Rovsing Dynamics [Member]
Business Acquisition [Line Items]
Acquisition date								Sep. 17, 2012
Cash purchase price										720
Fair value of contingent consideration										0
Total purchase price										720
Purchase price allocation:
Cash										20
Accounts receivable										0
Other assets										898
Property, plant and equipment										5
Amortizable intangible assets										800
Intangible assets										775
Goodwill										458
Total assets										2,156
Accounts payable and accrued expenses										428
Billings in excess of costs and estimated earnings on uncompleted contracts										1,008
Deferred tax liability										0
Total liabilities										1,436
Net assets acquired										720
Blessing White [Member]
Business Acquisition [Line Items]
Acquisition date								Oct. 01, 2012
Cash purchase price											10,529
Fair value of contingent consideration											0
Total purchase price											10,529
Purchase price allocation:
Cash											830
Accounts receivable											2,796
Other assets											527
Property, plant and equipment											76
Amortizable intangible assets											3,300
Intangible assets											3,280
Goodwill											6,070
Total assets											13,579
Accounts payable and accrued expenses											1,456
Billings in excess of costs and estimated earnings on uncompleted contracts											282
Deferred tax liability											1,312
Total liabilities											3,050
Net assets acquired											$ 10,529