CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
CONDENSED CONSOLIDATED BALANCE SHEETS [Abstract]
Accounts receivable, retainage	$ 594,926	$ 569,391
Accumulated depreciation	333,531	313,783
Accounts payable, retainage	264,336	258,294
Unamortized discount and debt issuance cost	$ 52,293	$ 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	49,694,018	49,211,353
Common stock, shares outstanding	49,694,018	49,211,353