CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Cash flows from operating activities:
Net income	$ 180,888	$ 126,145	$ 133,021
Adjustments to reconcile net income to net cash provided by (used in) operating activities (net of effect of acquisitions):
Depreciation and amortization	95,522	107,041	99,157
Stock-based compensation expense	15,131	11,833	7,441
Gain on sale of property and equipment	(44,786)	(48,104)	(31,890)
Gain on sale and leaseback transaction			(40,084)
Unrealized loss (gain) on interest rate swap	1,565	(397)	(5,581)
Other non-cash items	4,139	2,181	277
Changes in assets and liabilities:
Accounts receivable	(167,629)	(16,885)	(98,724)
Contract assets	62,677	(229,826)	(118,806)
Other current assets	18,379	45,578	(70,275)
Net deferred tax liabilities	4,998	29,429	14,695
Other long-term assets	39	459	932
Accounts payable	11,384	93,433	191,532
Contract liabilities	251,188	84,745	(7,869)
Operating lease assets and liabilities, net	(5,301)	(1,194)	(505)
Accrued liabilities	66,388	(6,832)	5,707
Other long-term liabilities	13,731	946	4,318
Net cash provided by (used in) operating activities	508,313	198,552	83,346
Cash flows from investing activities:
Purchase of property and equipment	(126,555)	(103,005)	(94,690)
Proceeds from sale of assets	99,323	63,695	41,302
Proceeds from sale and leaseback transaction, net of related expenses			49,887
Cash paid for acquisitions, net of cash and restricted cash acquired		9,300	(478,438)
Net cash (used in) investing activities	(27,232)	(30,010)	(481,939)
Cash flows from financing activities:
Borrowings under revolving lines of credit		440,223	188,560
Payments on revolving lines of credit		(540,223)	(88,560)
Proceeds from issuance of long-term debt		10,000	469,531
Payments on long-term debt	(224,470)	(96,987)	(86,769)
Payments related to tax withholding for stock-based compensation	(7,473)	(1,734)	(1,324)
Debt issuance costs			(6,643)
Dividends paid	(12,867)	(12,783)	(12,778)
Purchase of common stock			(5,990)
Other	452	(3,775)	(3,984)
Net cash used in financing activities	(244,358)	(205,279)	452,043
Effect of exchange rate changes on cash, cash equivalents and restricted cash	1,164	1,288	(102)
Net change in cash, cash equivalents and restricted cash	237,887	(35,449)	53,348
Cash, cash equivalents and restricted cash at beginning of the period	223,542	258,991	205,643
Cash, cash equivalents and restricted cash at end of the period	461,429	223,542	258,991
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION
Cash paid for interest	61,339	82,264	37,177
Cash paid for income taxes, net of refunds received	65,348	5,072	3,574
Value of transferable investment tax credits (ITC) purchased	40,000
Cash paid for transferable investment tax credits (ITC)	36,900
Leased assets obtained in exchange for new operating leases	228,674	260,396	98,127
SUPPLEMENTAL DISCLOSURES OF NONCASH INVESTING AND FINANCING ACTIVITIES
Dividends declared and not yet paid	$ 4,298	$ 3,202	$ 3,187