Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Cash flows from operating activities
Net income including noncontrolling interests	$ 207,915	$ 126,565	$ 88,952
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization	119,973	120,501	144,209
Amortization of debt issue costs	2,842	3,029	2,817
Loss (gain) on disposal of property and equipment	206	(164)	338
Provision for doubtful accounts	32	57	8
Deferred taxes	(8,914)	(844)	(3,468)
Foreign currency transaction gains and losses	(330)	1,973	4,916
Equity in losses (earnings) of unconsolidated joint ventures	47,751	(16,347)	(36,862)
Return on investments in unconsolidated joint ventures	48,970	28,417	24,494
Stock-based compensation	34,365	23,008	20,187
Contributions of treasury stock	58,172	54,659	54,905
Changes in assets and liabilities, net of acquisitions and newly consolidated joint ventures
Accounts receivable	(176,181)	(117,318)	99,894
Contract assets	(119,898)	(32,032)	1,494
Prepaid expenses and other assets	(95,415)	(1,405)	(18,798)
Accounts payable	24,497	(717)	(31,766)
Accrued expenses and other current liabilities	163,440	3,879	(74,683)
Contract liabilities	84,439	41,306	(30,407)
Income taxes	2,886	(3,649)	2,878
Other long-term liabilities	12,949	6,608	(43,534)
Net cash provided by operating activities	407,699	237,526	205,574
Cash flows from investing activities
Capital expenditures	(40,396)	(30,593)	(21,105)
Proceeds from sale of property and equipment	546	771	1,329
Payments for acquisitions, net of cash acquired	(221,937)	(379,467)	(198,256)
Investments in unconsolidated joint ventures	(119,582)	(17,622)	(38,459)
Return of investments in unconsolidated joint ventures	5,018	9,443	772
Proceeds from sales of investments in unconsolidated joint ventures	381	0	0
Net cash used in investing activities	(375,970)	(417,468)	(240,907)
Cash flows from financing activities
Proceeds from borrowings	620,900	969,700	0
Proceeds from delayed draw term loan	0	350,000	0
Repayments of borrowings	(620,900)	(969,700)	(50,000)
Repayment of private placement debt	0	(200,000)	0
Payments for debt costs and credit agreement	0	(862)	0
Payments for acquired warrants	0	(11,243)	0
Contributions by noncontrolling interests	2,867	10,266	1,754
Distributions to noncontrolling interests	(12,496)	(24,128)	(37,932)
Repurchases of common stock	(11,000)	(22,000)	(21,701)
Taxes paid on vested stock	(7,301)	(7,042)	(2,242)
Proceeds from issuance of common stock	6,059	5,377	5,555
Net cash (used in) provided by financing activities	(21,871)	100,368	(106,503)
Effect of exchange rate changes	546	(1,770)	(1,496)
Net increase (decrease) in cash, cash equivalents and restricted cash	10,404	(81,344)	(143,332)
Cash, cash equivalents and restricted cash
Beginning of year	262,539	343,883	487,215
End of year	272,943	262,539	343,883
Cash paid during the year for
Interest	30,273	20,819	14,993
Income taxes (net of refunds)	$ 74,133	$ 32,175	$ 22,461