CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Cash and cash equivalents ($37,445 and $0 related to variable interest entities ("VIEs"))	$ 172,927	$ 146,103
Accounts receivable ("AR")	1,838,359	1,743,300
Accounts receivable, retainage	602,581	569,391
Accumulated depreciation	339,045	313,783
Accounts payable ("AP")	899,284	994,016
Accounts payable, retainage	274,045	258,294
Billings in excess of costs and estimated earnings	339,808	331,112
Unamortized discount and debt issuance cost	$ 57,434	$ 56,072
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	49,760,256	49,211,353
Common stock, shares outstanding	49,760,256	49,211,353
Variable Interest Entity, Primary Beneficiary [Member]
Cash and cash equivalents ($37,445 and $0 related to variable interest entities ("VIEs"))	$ 37,445	$ 0
Accounts receivable ("AR")	56,912	0
Accounts payable ("AP")	57,888	0
Billings in excess of costs and estimated earnings	$ 30,293	$ 0