CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 59,456	$ 57,211
Adjustments to reconcile net income to net cash provided by operating activities-
Amortization of identifiable intangible assets	17,749	17,141
Depreciation expense	13,925	13,633
Change in right-of-use assets	8,554	8,687
Bad debt expense (benefit)	(429)	4,593
Deferred tax provision (benefit)	5,449	(2,980)
Amortization of debt financing costs	267	270
Gain on sale of assets	(841)	(866)
Changes in the fair value of contingent earn-out obligations	(5,767)	1,599
Stock-based compensation	6,860	5,188
(Increase) decrease in-
Receivables, net	(6,841)	30,258
Inventories	(5,365)	(220)
Prepaid expenses and other current assets	13,037	13,382
Costs and estimated earnings in excess of billings and unbilled accounts receivable	(2,752)	(6,185)
Other noncurrent assets	(1,105)	(228)
Increase (decrease) in-
Accounts payable and accrued liabilities	(10,964)	(1,984)
Billings in excess of costs and estimated earnings	27,510	22,082
Other long-term liabilities	(8,674)	2,205
Net cash provided by operating activities	110,069	163,786
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property and equipment	(10,762)	(14,539)
Proceeds from sales of property and equipment	1,530	1,378
Cash paid for acquisitions, net of cash acquired	(11,742)	(101,998)
Net cash used in investing activities	(20,974)	(115,159)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from revolving credit facility	25,000	178,000
Payments on revolving credit facility	(80,000)	(151,000)
Payments on term loan	(15,000)	(11,250)
Payments on other debt	(8,765)	(32,449)
Payments of dividends to stockholders	(8,341)	(7,674)
Share repurchase	(3,047)	(11,006)
Shares received in lieu of tax withholding	(2,363)	(1,076)
Proceeds from exercise of options	3,449	556
Deferred acquisition payments	(400)	(400)
Payments for contingent consideration arrangements	(865)	(9,863)
Net cash used in financing activities	(90,332)	(46,162)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	(1,237)	2,465
CASH AND CASH EQUIVALENTS, beginning of period	54,896	50,788
CASH AND CASH EQUIVALENTS, end of period	$ 53,659	$ 53,253