CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income including noncontrolling interests	$ 57,440	$ 28,599	$ 28,556
Adjustments to reconcile net income to net cash provided by operating activities
Amortization of identifiable intangible assets	7,481	7,653	7,132
Depreciation expense	15,935	13,683	11,440
Goodwill impairment		727
Bad debt expense	1,552	1,275	19
Deferred tax expense (benefit)	(414)	(4,579)	4,514
Amortization of debt financing costs	317	283	245
Gain on sale of assets	(880)	(830)	(589)
Changes in the fair value of contingent earn-out obligations	(225)	245	(1,646)
Stock-based compensation expense	5,609	4,806	3,974
(Increase) decrease in-
Receivables, net	(3,584)	(18,339)	(12,427)
Inventories	956	281	1,208
Prepaid expenses and other current assets	364	1,494	(109)
Costs and estimated earnings in excess of billings	(3,630)	2,744	(1,918)
Other noncurrent assets	(479)	(321)	(491)
Increase (decrease) in-
Accounts payable and accrued liabilities	11,617	(4,078)	6,776
Billings in excess of costs and estimated earnings	7,908	7,545	(9,226)
Other long-term liabilities	(2,100)	1,364	965
Net cash provided by operating activities	97,867	42,552	38,423
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property and equipment	(20,808)	(19,183)	(17,403)
Proceeds from sales of property and equipment	1,338	1,355	1,107
Proceeds from businesses sold			43
Cash paid for acquisitions, earn-outs and intangible assets, net of cash acquired	(6,158)	(56,314)
Net cash used in investing activities	(25,628)	(74,142)	(16,253)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from revolving line of credit	24,500	128,500	43,000
Payments on revolving line of credit	(53,000)	(90,000)	(43,000)
Payments on other long-term debt		(2,000)	(5,400)
Payments on capital lease obligations	(443)	(115)
Debt financing costs		(568)	(552)
Payments of dividends to stockholders	(9,358)	(8,444)	(7,875)
Share repurchase program	(8,330)	(7,974)	(1,832)
Shares received in lieu of tax withholding	(937)	(531)	(631)
Excess tax benefit of stock-based compensation	1,240	115	534
Proceeds from exercise of options	3,738	1,229	4,883
Distributions to noncontrolling interests	(4,904)	(8,612)
Payments for contingent consideration arrangements	(345)
Net cash provided by (used in) financing activities	(47,839)	11,600	(10,873)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	24,400	(19,990)	11,297
CASH AND CASH EQUIVALENTS, beginning of year-continuing operations and discontinued operations	32,064	52,054	40,757
CASH AND CASH EQUIVALENTS, end of year-continuing operations and discontinued operations	$ 56,464	$ 32,064	$ 52,054