Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Revenue
Total revenue	$ 669,913	$ 635,927
Cost of revenue
Total cost of revenue	606,595	612,128
Gross profit	63,318	23,799
Selling, general and administrative expenses	75,728	73,216
Non-cash impairment charges (see Note 3)	0	24,413
Other costs (see Note 3)	75,835	5,165
Gain on sales of property and equipment	(2,554)	(623)
Operating loss	(85,691)	(78,372)
Other (income) expense
Interest income	(256)	(1,291)
Interest expense	5,381	4,994
Equity in income of affiliates, net	(1,808)	(46)
Other (income) expense, net	(1,230)	5,219
Total other expense	2,087	8,876
Loss before benefit from income taxes	(87,778)	(87,248)
Benefit from income taxes	(22,455)	(14,710)
Net loss	(65,323)	(72,538)
Amount attributable to non-controlling interests	(872)	7,168
Net loss attributable to Granite Construction Incorporated	$ (66,195)	$ (65,370)
Net loss per share attributable to common shareholders (see Note 14)
Basic (in dollars per share)	$ (1.45)	$ (1.44)
Diluted (in dollars per share)	$ (1.45)	$ (1.44)
Weighted average shares of common stock
Basic (in shares)	45,697	45,520
Diluted (in shares)	45,697	45,520
Transportation [Member]
Revenue
Total revenue	$ 351,029	$ 350,901
Cost of revenue
Total cost of revenue	315,163	325,532
Water [Member]
Revenue
Total revenue	99,753	101,657
Cost of revenue
Total cost of revenue	91,187	92,310
Specialty [Member]
Revenue
Total revenue	155,674	133,039
Cost of revenue
Total cost of revenue	138,349	143,758
Materials [Member]
Revenue
Total revenue	63,457	50,330
Cost of revenue
Total cost of revenue	$ 61,896	$ 50,528