Condensed Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021
Cash and cash equivalents	$ 360,911	$ 395,647	$ 440,833
Receivables, net	380,502	464,588	393,283
Contract assets	180,023	145,437	144,780
Other current assets	179,024	177,210	59,938
Property and equipment, net	450,250	433,504	426,953
Accounts payable	285,390	324,313	269,497
Contract liabilities	165,358	200,041	153,633
Accrued expenses and other current liabilities	$ 439,525	$ 452,829	$ 499,827
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	3,000,000	3,000,000	3,000,000
Preferred stock, shares outstanding (in shares)	0	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	150,000,000	150,000,000	150,000,000
Common stock, shares issued (in shares)	45,364,137	45,840,260	45,791,712
Common stock, shares outstanding (in shares)	45,364,137	45,840,260	45,791,712
Consolidated Construction Corporate Joint Venture [Member]
Cash and cash equivalents	$ 100,080	$ 92,783	$ 110,486
Receivables, net	48,795	49,534	32,539
Contract assets	63,952	50,054	37,683
Other current assets	6,841	8,091	12,298
Property and equipment, net	13,458	14,920	22,457
Accounts payable	57,955	55,012	52,217
Contract liabilities	55,085	69,328	70,968
Accrued expenses and other current liabilities	$ 7,535	$ 5,514	$ 4,460