CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Cash and cash equivalents	$ 149,881	$ 116,075
Accounts receivable	1,469,213	1,261,072
Retainage receivable	508,423	478,744
Other current assets	165,688	115,527
Accumulated depreciation	362,350	343,735
PROPERTY AND EQUIPMENT, net of accumulated depreciation	502,675	490,669
Accounts payable	685,745	621,728
Accrued expenses and other current liabilities	175,525	174,325
Billings in excess of costs and estimated earnings	635,924	573,190
Unamortized discounts and debt issuance costs	$ 29,305	$ 34,998
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, par value (in dollars per share)	$ 1	$ 1
Preferred stock, shares issued	0	0
Common stock, shares authorized	75,000,000	75,000,000
Common stock, par value (in dollars per share)	$ 1	$ 1
Common stock, shares issued	50,278,816	50,025,996
Common stock, shares outstanding	50,278,816	50,025,996
Variable Interest Entity, Primary Beneficiary [Member]
Cash and cash equivalents	$ 60,562	$ 43,131
Accounts receivable	94,807	62,482
Retainage receivable	56,012	36,724
Other current assets	35,051	30,185
PROPERTY AND EQUIPMENT, net of accumulated depreciation	53,818	51,508
Accounts payable	36,524	18,070
Accrued expenses and other current liabilities	42,109	34,828
Billings in excess of costs and estimated earnings	$ 282,130	$ 263,764