Note 16 - Weighted Average Shares Outstanding and Net Loss Per Share - Reconciliation of the Weighted Average Shares Outstanding in Basic and Diluted Net Loss per Share (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
Net loss attributable to Granite Construction Incorporated		$ (65,370)	$ (62,470)
Weighted average common shares outstanding, basic (in shares)		45,520	46,699
Dilutive effect of RSUs and convertible notes (in shares)	[1],[2]	0	0
Weighted average common shares outstanding, diluted (in shares)		45,520	46,699
Net loss per share, basic (in dollars per share)		$ (1.44)	$ (1.34)
Net loss per share, diluted (in dollars per share)		$ (1.44)	$ (1.34)

[1] As the average price of our common stock since the issuance date of the 2.75% Convertible Notes was below $31.47 per share, the number of shares used in calculating diluted net loss per share for the three months ended March 31, 2020 excluded the potential dilution from the 2.75% Convertible Notes converting into shares of common stock.

[2] Due to the net loss for the three months ended March 31, 2020 and 2019, RSUs representing approximately 443,000 and 422,000 shares, respectively, have been excluded from the number of shares used in calculating diluted net loss per share, as their inclusion would be antidilutive.