CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 48,055	$ 38,173	$ 40,476	$ 46,936
Other comprehensive income (loss), net of tax:
Net unrealized gain (loss) on derivatives	46	382	(163)	(1,016)
Less: reclassification for net losses included in interest expense	25	126	141	226
Net change	71	508	(22)	(790)
Foreign currency translation adjustments, net	98	(221)	633	766
Other comprehensive income (loss)	169	287	611	(24)
Comprehensive income	48,224	38,460	41,087	46,912
Non-controlling interests in comprehensive income	(2,073)	(982)	(4,151)	(5,987)
Comprehensive income attributable to Granite	$ 46,151	$ 37,478	$ 36,936	$ 40,925