CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Cash flows from operating activities:
Net income	$ 91,520	$ 86,199
Adjustments to reconcile net income to net cash (used in) provided by operating activities (net of effect of acquisitions):
Depreciation and amortization	69,348	78,865
Stock-based compensation expense	5,748	9,146
Gain on sale of property and equipment	(17,987)	(13,075)
Gain on sale and leaseback transaction	(40,084)
Unrealized gain on interest rate swap	(5,616)	(3,183)
Other non-cash items	1,877	823
Changes in assets and liabilities:
Accounts receivable	(122,867)	(69,659)
Contract assets	(148,044)	(54,262)
Other current assets	(98,489)	(21,070)
Other long-term assets	1,975	477
Accounts payable	133,731	57,698
Contract liabilities	(10,364)	(67,821)
Operating lease assets and liabilities, net	(896)	(1,388)
Accrued liabilities	40,016	21,327
Other long-term liabilities	(1,903)	(8,457)
Net cash (used in) provided by operating activities	(102,035)	15,620
Cash flows from investing activities:
Purchase of property and equipment	(75,696)	(102,133)
Proceeds from sale of assets	19,237	43,488
Proceeds from sale and leaseback transaction, net of related expenses	49,887
Cash paid for acquisitions, net of cash and restricted cash acquired	(478,438)	(606,974)
Net cash used in investing activities	(485,010)	(665,619)
Cash flows from financing activities:
Proceeds from issuance of long-term debt	469,531	461,719
Payments on long-term debt	(77,751)	(96,473)
Proceeds from issuance of common stock	596	178,707
Debt issuance costs	(6,643)	(4,876)
Dividends paid	(9,583)	(9,334)
Purchase of common stock	(5,990)
Other	(4,947)	(7,038)
Net cash provided by financing activities	515,352	522,705
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(924)	300
Net change in cash, cash equivalents and restricted cash	(72,617)	(126,994)
Cash, cash equivalents and restricted cash at beginning of the period	205,643	330,975
Cash, cash equivalents and restricted cash at end of the period	133,026	203,981
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION
Cash paid for interest	20,025	16,555
Cash paid for income taxes, net of refunds received	2,540	31,194
Leased assets obtained in exchange for new operating leases	40,144	15,500
SUPPLEMENTAL DISCLOSURES OF NONCASH INVESTING AND FINANCING ACTIVITIES
Dividends declared and not yet paid	3,195	3,228
Revolving Credit Facility
Cash flows from financing activities:
Borrowings under revolving line of credit or credit facility	150,000	100,000
Payments on revolving line of credit or credit facility		$ (100,000)
Canadian Credit Facility
Cash flows from financing activities:
Borrowings under revolving line of credit or credit facility	19,943
Payments on revolving line of credit or credit facility	$ (19,804)