Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Cash flows from operating activities:
Net income	$ 22,688	$ 17,860	$ 12,732
Adjustments to reconcile net income to net cash provided by operating activities:
Gain on reversal of deferred rent liability	0	(1,041)	0
Income tax benefit on reduction of uncertain tax position liabilities	(1,602)	(891)	0
Loss (gain) on change in fair value of contingent consideration, net	789	(517)	(1,313)
Depreciation and amortization	7,971	6,187	4,230
Non-cash compensation expense	3,615	3,100	2,012
Deferred income taxes	716	147	935
Changes in other operating items, net of acquired amounts:
Accounts and other receivables	(11,262)	(4,955)	(13)
Costs and estimated earnings in excess of billings on uncompleted contracts	(1,256)	(701)	(1,771)
Prepaid expenses and other current assets	(1,227)	(1,599)	1,754
Accounts payable and accrued expenses	4,003	(216)	5,403
Billings in excess of costs and estimated earnings on uncompleted contracts	3,218	168	2,084
Income tax benefit of stock-based compensation	(2,034)	(131)	(129)
Contingent consideration payments in excess of fair value on acquisition date	(602)	(721)	0
Other	295	(491)	266
Net cash provided by operating activities	25,312	16,199	26,190
Cash flows from investing activities:
Additions to property, plant and equipment	(2,536)	(3,975)	(1,531)
Acquisitions, net of cash acquired	(12,184)	(36,077)	(5,121)
Other investing activities	0	(157)	0
Net cash used in investing activities	(14,720)	(40,209)	(6,652)
Cash flows from financing activities:
Contingent consideration payments	(1,263)	(1,238)	(775)
Change in negative cash book balance	(1,888)	1,883	5
Repurchases of common stock in the open market	(3,433)	(1,414)	(266)
Income tax benefit from stock-based compensation	2,034	131	129
Tax withholding payments for employee stock-based compensation in exchange for shares surrendered	(2,750)	(337)	(361)
Proceeds from issuance of common stock	284	355	39
Other financing activities	(126)	(8)	(141)
Net cash used in financing activities	(7,142)	(628)	(1,370)
Effect of exchange rate changes on cash and cash equivalents	160	(113)	(69)
Net change in cash and cash equivalents	3,610	(24,751)	18,099
Cash and cash equivalents at beginning of year	4,151	28,902	10,803
Cash and cash equivalents at end of year	7,761	4,151	28,902
Cash paid during the year for:
Interest	104	100	36
Income taxes	$ 12,532	$ 10,078	$ 5,570