CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 107,299	$ 80,272
Adjustments to reconcile net income to net cash provided by operating activities-
Amortization of identifiable intangible assets	25,306	20,221
Depreciation expense	20,818	18,222
Change in right-of-use assets	12,338	10,552
Bad debt expense	5,318	2,093
Deferred tax provision (benefit)	1,197	(2,620)
Amortization of debt financing costs	408	287
Gain on sale of assets	(1,243)	(1,119)
Changes in the fair value of contingent earn-out obligations	(1,824)	3,924
Stock-based compensation	5,949	4,861
(Increase) decrease in-
Receivables, net	33,304	(31,647)
Inventories	(708)	(248)
Prepaid expenses and other current assets	9,417	(4,625)
Costs and estimated earnings in excess of billings and unbilled accounts receivable	(7,007)	(2,081)
Other noncurrent assets	(631)	(544)
Increase (decrease) in-
Accounts payable and accrued liabilities	(16,030)	6,635
Billings in excess of costs and estimated earnings	13,489	4,555
Other long-term liabilities	9,000	(9,023)
Net cash provided by operating activities	216,400	99,715
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property and equipment	(19,459)	(22,641)
Proceeds from sales of property and equipment	1,890	1,447
Proceeds from sale of business		1,611
Cash paid for acquisitions, net of cash acquired	(112,945)	(196,470)
Net cash used in investing activities	(130,514)	(216,053)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from revolving credit facility	198,000	320,000
Payments on revolving credit facility	(164,500)	(177,000)
Payments on term loan	(15,000)
Payments on other debt	(44,464)	(3,254)
Payments of dividends to stockholders	(11,507)	(10,871)
Share repurchase	(18,777)	(15,317)
Shares received in lieu of tax withholding	(1,076)	(1,498)
Proceeds from exercise of options	1,555	1,001
Deferred acquisition payments	(500)	(637)
Payments for contingent consideration arrangements	(9,865)	(1,343)
Net cash provided by (used in) financing activities	(66,134)	111,081
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	19,752	(5,257)
CASH AND CASH EQUIVALENTS, beginning of period	50,788	45,620
CASH AND CASH EQUIVALENTS, end of period	$ 70,540	$ 40,363