Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Operating activities
Net income	$ 29,587	$ 78,857	$ 2,414
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, depletion and amortization	92,270	82,569	109,050
Amortization related to long-term debt	2,390	2,366	9,448
Non-cash loss on debt extinguishment	51,052	0	0
Gain on sales of property and equipment, net	(28,346)	(12,617)	(66,439)
Deferred income taxes	26,556	5,447	16,600
Stock-based compensation	10,477	7,765	6,407
Equity in net loss from unconsolidated construction joint ventures	18,617	19,676	765
Net income from affiliates	(25,748)	(13,571)	(12,586)
Other non-cash adjustments	5,695	222	0
Changes in assets and liabilities:
Receivables	(128,099)	59,623	(11,317)
Contract assets, net	49,691	(113,410)	12,046
Inventories	(1,430)	(14,307)	774
Contributions to unconsolidated construction joint ventures	(21,323)	(53,787)	(61,780)
Distributions from unconsolidated construction joint ventures and affiliates	29,337	19,223	22,004
Deposit for legal settlement	0	129,000	(129,000)
Other assets, net	(17,718)	16,868	(11,969)
Accounts payable	66,828	(9,778)	7,396
Accrual for legal settlement	0	(129,000)	129,000
Accrued expenses and other liabilities, net	23,871	(19,499)	(882)
Net cash provided by operating activities	183,707	55,647	21,931
Investing activities
Purchases of marketable securities	(9,740)	(94,104)	(10,000)
Maturities of marketable securities	40,000	45,000	0
Proceeds from called marketable securities	0	6	0
Purchases of property and equipment	(140,384)	(121,612)	(94,810)
Proceeds from sales of property and equipment	38,109	26,064	94,802
Proceeds from company-owned life insurance	1,545	0	0
Proceeds from the sale of business	0	140,576	0
Acquisition of businesses, net of cash acquired	(294,018)	0	0
Issuance of notes receivable	0	(7,560)	(20,400)
Collection of notes receivable	5,198	630	8,930
Net cash used in investing activities	(359,290)	(11,000)	(21,478)
Financing activities
Proceeds from debt	305,000	50,000	0
Debt principal repayments	(305,118)	(125,164)	(8,922)
Capped call transactions	(53,035)	0	0
Redemption of warrants	(13,201)	0	0
Proceeds from issuance of 3.75% Convertible Notes	373,750	0	0
Debt issuance costs	(10,865)	0	0
Cash dividends paid	(22,811)	(23,271)	(23,804)
Repurchases of common stock	(4,124)	(70,898)	(2,730)
Contributions from non-controlling partners	43,300	13,150	20,126
Distributions to non-controlling partners	(14,224)	(8,567)	(9,514)
Other financing activities, net	583	439	398
Net cash provided by (used in) financing activities	299,255	(164,311)	(24,446)
Net increase (decrease) in cash, cash equivalents and restricted cash	123,672	(119,664)	(23,993)
Cash, cash equivalents and $0, $1,512 and $1,512 in restricted cash at beginning of period	293,991	413,655	437,648
Cash, cash equivalents and $0, $0 and $1,512 in restricted cash at end of period	417,663	293,991	413,655
Supplementary Information
Right of use assets obtained in exchange for lease obligations	39,361	17,547	23,379
Operating lease liabilities	21,458	22,611	23,203
Interest	15,640	11,511	14,593
Income taxes	15,381	3,768	2,066
Other non-cash operating activities:
Performance guarantees	(6,854)	(17,409)	(167)
Deferred taxes related to capped call transactions	13,394	0	0
Non-cash investing and financing activities:
RSUs issued, net of forfeitures	11,649	8,694	8,299
Dividends declared but not paid	5,713	5,687	5,959
Contributions from non-controlling partners	2,475	4,110	9,006
Accrued equipment purchases	$ 152	$ 5,745	$ (4,714)