Reportable Segments (Details) $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2016 USD ($)	Sep. 30, 2016 USD ($)	Jun. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Sep. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Mar. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Sep. 30, 2014 USD ($)	Jun. 30, 2014 USD ($)	Mar. 31, 2014 USD ($)	Dec. 31, 2016 USD ($) segment	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Segment reporting information
Number of reportable segments | segment													3
Revenue	$ 601,863	$ 507,828	$ 456,811	$ 430,446	$ 497,145	$ 555,945	$ 483,545	$ 392,780	$ 487,592	$ 613,237	$ 515,291	$ 470,074	$ 1,996,948	$ 1,929,415	$ 2,086,194
% of Total Revenue													100.00%	100.00%	100.00%
Gross Profit	68,616	50,129	$ 43,285	$ 39,277	63,725	$ 71,647	$ 46,496	$ 38,005	$ 49,616	$ 75,473	$ 61,194	$ 49,757	$ 201,307	$ 219,873	$ 236,040
% of Revenue													10.10%	11.40%	11.30%
Goodwill	127,226				124,161								$ 127,226	$ 124,161
Goodwill impairment charge					401								2,716	401
West
Segment reporting information
Revenue													$ 1,041,341	$ 913,626	$ 964,093
% of Total Revenue													52.20%	47.40%	46.20%
Gross Profit													$ 145,239	$ 130,255	$ 143,468
% of Revenue													13.90%	14.30%	14.90%
Goodwill	45,239				45,239								$ 45,239	$ 45,239
East
Segment reporting information
Revenue													$ 521,301	$ 612,174	$ 489,926
% of Total Revenue													26.10%	31.70%	23.50%
Gross Profit													$ (15,938)	$ 42,523	$ 25,749
% of Revenue													(3.10%)	6.90%	5.30%
Goodwill	40,150				42,866								$ 40,150	$ 42,866
East | JCG | Texas Heavy Civil Business unit
Segment reporting information
Goodwill impairment charge		$ 2,716
Energy
Segment reporting information
Revenue													$ 434,306	$ 403,615	$ 632,175
% of Total Revenue													21.70%	20.90%	30.30%
Gross Profit													$ 72,006	$ 47,095	$ 66,823
% of Revenue													16.60%	11.70%	10.60%
Goodwill	$ 41,837				$ 36,056								$ 41,837	$ 36,056