CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 16,272	$ 18,526	$ (7,579)	$ 8,763
Other comprehensive income (loss), net of tax:
Net unrealized loss on derivatives	(261)	(507)	(209)	(1,398)
Less: reclassification for net losses included in interest expense	47	100	116	100
Net change	(214)	(407)	(93)	(1,298)
Foreign currency translation adjustments, net	542	165	535	987
Other comprehensive income (loss)	328	(242)	442	(311)
Comprehensive income (loss)	16,600	18,284	(7,137)	8,452
Non-controlling interests in comprehensive loss	(2,139)	(4,327)	(2,078)	(5,005)
Comprehensive income (loss) attributable to Granite	$ 14,461	$ 13,957	$ (9,215)	$ 3,447