CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenue
Construction	$ 1,664,708	$ 1,365,198	$ 1,262,675
Large Project Construction	1,032,229	888,193	812,720
Construction Materials	292,776	261,226	295,634
Total revenue	2,989,713	2,514,617	2,371,029
Cost of revenue
Construction	1,417,694	1,155,983	1,075,169
Large Project Construction	1,002,436	824,056	733,253
Construction Materials	254,650	233,208	262,771
Total cost of revenue	2,674,780	2,213,247	2,071,193
Gross profit	314,933	301,370	299,836
Selling, general and administrative expenses	222,811	219,299	203,817
Restructuring gains	(2,411)	(1,925)	(6,003)
Gain on sales of property and equipment	(4,182)	(8,358)	(8,286)
Operating income	98,715	92,354	110,308
Other (income) expense
Interest income	(4,742)	(3,225)	(2,135)
Interest expense	10,800	12,366	14,257
Equity in income of affiliates	(7,107)	(7,177)	(3,210)
Other income, net	(4,699)	(5,972)	(2,031)
Total other (income) expense	(5,748)	(4,008)	6,881
Income before provision for income taxes	104,463	96,362	103,427
Provision for income taxes	28,662	30,162	35,179
Net income	75,801	66,200	68,248
Amount attributable to non-controlling interests	(6,703)	(9,078)	(7,763)
Net income attributable to Granite Construction Incorporated	$ 69,098	$ 57,122	$ 60,485
Net income per share attributable to common shareholders (see Note 14)
Basic (in dollars per share)	$ 1.74	$ 1.44	$ 1.54
Diluted (in dollars per share)	$ 1.71	$ 1.42	$ 1.52
Weighted average shares of common stock
Weighted average common stock outstanding, basic (in shares)	39,795	39,557	39,337
Weighted average common stock outstanding, diluted (in shares)	40,372	40,225	39,868
Dividends per common share (in dollars per share)	$ 0.52	$ 0.52	$ 0.52