CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Cash flows from operating activities:
Net income	$ 33,888	$ 330,729	$ 322,699
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	371,240	345,612	258,841
Amortization of intangible assets	135,908	77,214	38,910
Non-cash stock-based compensation expense	27,446	24,805	21,875
Provision for deferred income taxes	9,549	51,931	7,180
Equity in earnings of unconsolidated affiliates, net	(28,836)	(33,830)	(29,738)
Gains on sales of assets, net	(39,692)	(35,635)	(16,210)
Non-cash interest expense, net	4,172	3,171	2,988
Other non-cash items, net	4,743	(12,323)	21,775
Changes in assets and liabilities, net of acquisitions:
Accounts receivable	6,298	149,152	87,372
Contract assets	(304,351)	49,295	63,306
Inventories	(20,523)	10,147	17,904
Other assets, current and long-term portion	68,603	(35,837)	20,486
Accounts payable and accrued expenses	192,119	(104,481)	94,069
Contract liabilities	(39,372)	10,603	21,326
Other liabilities, current and long-term portion	(68,895)	(37,479)	4,471
Net cash provided by operating activities	352,297	793,074	937,254
Cash flows from investing activities:
Cash paid for acquisitions, net of cash acquired	(635,763)	(1,244,603)	(24,971)
Capital expenditures	(263,352)	(170,066)	(213,746)
Proceeds from sale of property and equipment	81,470	65,287	37,077
Payments for other investments	(3,981)	(9,996)	(17,456)
Proceeds from other investments	400	557	648
Other investing activities, net	43	1,650	1,843
Net cash used in investing activities	(821,183)	(1,357,171)	(216,605)
Cash flows from financing activities:
Proceeds from credit facilities and term loans	4,065,000	1,503,372	1,434,610
Repayments of credit facilities	(3,241,128)	(812,103)	(1,741,067)
Proceeds from issuance of 4.50% senior notes	0	0	600,000
Repayments of 4.875% senior notes	0	0	(400,000)
Payments of finance lease obligations	(181,481)	(158,892)	(126,988)
Payments of acquisition-related contingent consideration	(35,149)	(21,675)	(10,097)
Payments for acquisition-related contingent assets	(17,636)	0	0
Payments to non-controlling interests, including acquisition of interests	(728)	(8,965)	(719)
Proceeds from stock-based awards	0	0	7,090
Payments for stock-based awards	(4,098)	(6,024)	(636)
Repurchases of common stock	(81,291)	0	(120,228)
Other financing activities, net	(22,592)	6,229	(11,852)
Net cash provided by (used in) financing activities	480,897	501,942	(369,887)
Effect of currency translation on cash	(2,155)	(227)	929
Net increase (decrease) in cash and cash equivalents	9,856	(62,382)	351,691
Cash and cash equivalents - beginning of period	360,736	423,118	71,427
Cash and cash equivalents - end of period	370,592	360,736	423,118
Supplemental cash flow information:
Interest paid	106,484	61,815	65,016
Income taxes paid, net of refunds	8,603	69,110	64,651
Supplemental disclosure of non-cash information:
Additions to property and equipment from finance leases	$ 206,620	$ 160,286	$ 114,221