CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 38,087	$ 32,180	$ 46,034	$ 33,109
Other comprehensive income (loss), net of tax:
Net unrealized gain (loss) on derivatives	382	0	(1,016)	0
Less: reclassification for net losses included in interest expense	126	0	226	0
Net change	508	0	(790)	0
Foreign currency translation adjustments, net	(221)	(273)	766	(669)
Other comprehensive income (loss)	287	(273)	(24)	(669)
Comprehensive income	38,374	31,907	46,010	32,440
Non-controlling interests in comprehensive income	(982)	(1,421)	(5,987)	(1,297)
Comprehensive income attributable to Granite	$ 37,392	$ 30,486	$ 40,023	$ 31,143