CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 105,753	$ 107,299
Adjustments to reconcile net income to net cash provided by operating activities-
Amortization of identifiable intangible assets	28,934	25,306
Depreciation expense	21,066	20,818
Change in right-of-use assets	12,904	12,338
Bad debt expense (benefit)	(1,698)	5,318
Deferred tax provision	6,589	1,197
Amortization of debt financing costs	403	408
Gain on sale of assets	(1,021)	(1,243)
Changes in the fair value of contingent earn-out obligations	(4,523)	(1,824)
Stock-based compensation	7,378	5,949
(Increase) decrease in-
Receivables, net	(25,809)	33,304
Inventories	(6,248)	(708)
Prepaid expenses and other current assets	15,592	9,417
Costs and estimated earnings in excess of billings and unbilled accounts receivable	(8,698)	(7,007)
Other noncurrent assets	(1,248)	(631)
Increase (decrease) in-
Accounts payable and accrued liabilities	15,112	(16,030)
Billings in excess of costs and estimated earnings	257	13,489
Other long-term liabilities	(12,089)	9,000
Net cash provided by operating activities	152,654	216,400
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property and equipment	(15,864)	(19,459)
Proceeds from sales of property and equipment	1,802	1,890
Cash paid for acquisitions, net of cash acquired	(105,543)	(112,945)
Net cash used in investing activities	(119,605)	(130,514)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from revolving credit facility	160,000	198,000
Payments on revolving credit facility	(115,000)	(164,500)
Payments on term loan	(15,000)	(15,000)
Payments on other debt	(9,000)	(44,464)
Payments on finance lease liabilities	(207)
Payments of dividends to stockholders	(12,691)	(11,507)
Share repurchase	(25,531)	(18,777)
Shares received in lieu of tax withholding	(2,363)	(1,076)
Proceeds from exercise of options	3,449	1,555
Deferred acquisition payments	(400)	(500)
Payments for contingent consideration arrangements	(3,481)	(9,865)
Net cash used in financing activities	(20,224)	(66,134)
NET INCREASE IN CASH AND CASH EQUIVALENTS	12,825	19,752
CASH AND CASH EQUIVALENTS, beginning of period	54,896	50,788
CASH AND CASH EQUIVALENTS, end of period	$ 67,721	$ 70,540