Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Income Statement [Abstract]
Revenue	$ 1,125,964	$ 1,082,486	$ 1,825,511	$ 1,754,761
Cost of revenue	926,865	917,775	1,542,563	1,535,765
Gross profit	199,099	164,711	282,948	218,996
Selling, general and administrative expenses	85,887	70,052	201,798	158,045
Other costs, net	13,253	10,225	22,679	21,235
Gain on sales of property and equipment, net	(3,606)	(1,387)	(5,343)	(2,805)
Operating income	103,565	85,821	63,814	42,521
Other (income) expense
Loss on debt extinguishment	0	27,824	0	27,824
Interest income	(5,761)	(3,600)	(12,029)	(10,302)
Interest expense	7,927	5,337	15,684	13,420
Net income from affiliates	(3,698)	(4,557)	(4,792)	(8,527)
Other (income) expense, net	(2,462)	1,267	(2,525)	(476)
Total other (income) expense, net	(3,994)	26,271	(3,662)	21,939
Income before income taxes	107,559	59,550	67,476	20,582
Provision for income taxes	27,214	20,693	15,458	11,167
Net income	80,345	38,857	52,018	9,415
Amount attributable to non-controlling interests	(8,645)	(1,962)	(13,974)	(3,503)
Net income attributable to Granite Construction Incorporated	$ 71,700	$ 36,895	$ 38,044	$ 5,912
Net loss per share attributable to common shareholders
Basic (USD per share)	$ 1.64	$ 0.84	$ 0.87	$ 0.13
Diluted (USD per share)	$ 1.42	$ 0.76	$ 0.84	$ 0.13
Weighted average shares outstanding:
Basic (shares)	43,746	44,060	43,605	44,024
Diluted (shares)	52,755	52,727	52,616	44,593