CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Cash, including cash equivalents	$ 192,868	$ 146,103
Cash equivalents	1,481	15,302
Accounts receivable	1,801,656	1,743,300
Accounts receivable, retainage	535,939	569,391
Total property and equipment, net ($11,641 and $0 related to VIEs)	467,499	477,626
Accounts payable	961,791	994,016
Contract payable retainage	261,820	258,294
Billings in excess of costs and estimated earnings	456,869	331,112
Unamortized discount and debt issuance cost	$ 45,631	$ 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	49,781,010	49,211,353
Common stock, shares outstanding	49,781,010	49,211,353
Variable Interest Entity, Primary Beneficiary [Member]
Cash, including cash equivalents	$ 53,067	$ 0
Accounts receivable	42,413	0
Total property and equipment, net ($11,641 and $0 related to VIEs)	11,641	0
Accounts payable	19,243	0
Billings in excess of costs and estimated earnings	$ 120,952	$ 0