CONSOLIDATED STATEMENTS OF CASH FLOWS $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Cash flows from operating activities:
Net income	$ 133,021	$ 115,739	$ 104,983
Adjustments to reconcile net income to net cash provided by operating activities (net of effect of acquisitions):
Depreciation and amortization	99,157	105,559	82,497
Stock-based compensation expense	7,441	10,462	2,274
Gain on sale of property and equipment	(31,890)	(15,921)	(8,059)
Gain on sale and leaseback transaction	(40,084)
Unrealized (gain) loss on interest rate swap	(5,581)	(4,859)	2,762
Other non-cash items	277	1,381	374
Changes in assets and liabilities:
Accounts receivable	(98,724)	10,540	(30,035)
Contract assets	(118,806)	(66,999)	19,288
Other current assets	(70,275)	(54,725)	13,562
Net deferred tax liabilities (assets)	14,695	25,564	(5,080)
Other long-term assets	932	(1,683)	2,170
Accounts payable	191,532	15,701	9,577
Contract liabilities	(7,869)	(29,111)	74,791
Operating lease assets and liabilities, net	(505)	(2,605)	747
Accrued liabilities	5,707	(24,700)	20,142
Other long-term liabilities	4,318	(4,596)	23,008
Net cash provided by operating activities	83,346	79,747	313,001
Cash flows from investing activities:
Purchase of property and equipment	(94,690)	(133,842)	(64,357)
Proceeds from sale of assets	41,302	49,548	21,851
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	(481,939)	(691,268)	(42,506)
Cash flows from financing activities:
Borrowings under revolving line of credit or credit facility	188,560	100,000
Payments on revolving line of credit or credit facility	(88,560)	(100,000)
Proceeds from issuance of long-term debt	469,531	461,719	33,873
Payments on long-term debt	(86,769)	(113,851)	(68,884)
Proceeds from issuance of common stock	585	178,707	578
Debt issuance costs	(6,643)	(4,876)
Dividends paid	(12,778)	(12,565)	(11,594)
Purchase of common stock	(5,990)	(14,720)	(11,453)
Other	(5,893)	(8,681)	(5,343)
Net cash provided by (used in) financing activities	452,043	485,733	(62,823)
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(102)	456	(140)
Net change in cash, cash equivalents and restricted cash	53,348	(125,332)	207,532
Cash, cash equivalents and restricted cash at beginning of the year	205,643	330,975	123,443
Cash, cash equivalents and restricted cash at end of the year	258,991	205,643	330,975
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION
Cash paid for interest	37,177	22,224	17,216
Cash paid for income taxes, net of refunds received	3,574	39,256	26,594
Leased assets obtained in exchange for new operating leases	98,127	17,149	54,803
SUPPLEMENTAL DISCLOSURE OF NONCASH INVESTING AND FINANCING ACTIVITIES
Dividends declared and not yet paid	$ 3,187	$ 3,192	$ 2,887