CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS [Abstract]
REVENUE	$ 1,117,361	$ 1,085,369
COST OF OPERATIONS	(1,014,641)	(980,277)
GROSS PROFIT	102,720	105,092
General and administrative expenses	(65,703)	(64,970)
INCOME FROM CONSTRUCTION OPERATIONS	37,017	40,122
Other income, net	417	682
Interest expense	(15,564)	(14,080)
INCOME BEFORE INCOME TAXES	21,870	26,724
Provision for income taxes	(8,106)	(11,324)
NET INCOME	$ 13,764	$ 15,400
BASIC EARNINGS PER COMMON SHARE (in dollars per share)	$ 0.28	$ 0.31
DILUTED EARNINGS PER COMMON SHARE (in dollars per share)	$ 0.27	$ 0.31
WEIGHTED AVERAGE COMMON SHARES OUTSTANDING:
BASIC (in shares)	49,282	49,079
DILUTED (in shares)	50,948	49,285