Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Cash flows from operating activities:
Net income (loss)	$ 16,255	$ 75,765	$ (18,704)	$ 141,877
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Depreciation	87,001	87,501	172,195	166,766
Amortization of intangible assets	27,673	19,923	53,263	31,170
Non-cash stock-based compensation expense			13,172	11,600
Provision for (benefit from) deferred income taxes			6,190	(1,594)
Equity in earnings of unconsolidated affiliates, net	(6,587)	(7,525)	(13,364)	(14,871)
Gains on sales of assets, net			(8,662)	(5,975)
Non-cash interest expense, net			1,709	1,563
Other non-cash items, net			301	(7,836)
Changes in assets and liabilities, net of acquisitions:
Accounts receivable			18,575	32,710
Contract assets			(289,018)	(46,148)
Inventories			(19,844)	5,167
Other assets, current and long-term portion			521	(2,604)
Accounts payable and accrued expenses			99,796	60,452
Contract liabilities			(11,915)	(16,020)
Other liabilities, current and long-term portion			(2,674)	(6,915)
Net cash provided by operating activities			1,541	349,342
Cash flows from investing activities:
Cash paid for acquisitions, net of cash acquired			(44,908)	(589,055)
Capital expenditures			(189,870)	(97,029)
Proceeds from sale of property and equipment			17,722	12,960
Payments for other investments			(2,965)	(6,197)
Proceeds from other investments			0	557
Other investing activities, net			0	2,650
Net cash used in investing activities			(220,021)	(676,114)
Cash flows from financing activities:
Proceeds from credit facilities			1,954,650	414,741
Repayments of credit facilities			(1,741,083)	(161,375)
Payments of finance lease obligations			(83,375)	(76,630)
Repurchases of common stock			(81,291)	0
Payments of acquisition-related contingent consideration			(26,779)	(20,893)
Payments for acquisition-related contingent assets			(17,636)	0
Payments to non-controlling interests, including acquisition of interests			0	(8,888)
Payments for stock-based awards			(4,024)	(3,774)
Other financing activities, net			(3,446)	(2,343)
Net cash (used in) provided by financing activities			(2,984)	140,838
Effect of currency translation on cash			(343)	87
Net decrease in cash and cash equivalents			(221,807)	(185,847)
Cash and cash equivalents - beginning of period			360,736	423,118	$ 423,118
Cash and cash equivalents - end of period	$ 138,929	$ 237,271	138,929	237,271	$ 360,736
Supplemental cash flow information:
Interest paid			34,507	28,401
Income tax payments, net			1,304	61,180
Supplemental disclosure of non-cash information:
Additions to property and equipment from finance leases			$ 126,669	$ 98,984