CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (9,662)	$ (23,851)
Other comprehensive income (loss), net of tax:
Net unrealized gain on derivatives	620	52
Less: reclassification for net (gains) losses included in interest expense	(40)	69
Net change	580	121
Foreign currency translation adjustments, net	(17)	(7)
Other comprehensive income	563	114
Comprehensive loss	(9,099)	(23,737)
Non-controlling interests in comprehensive loss	(1,761)	61
Comprehensive loss attributable to Granite	$ (10,860)	$ (23,676)