Note 12 - Investments in Affiliates - Summarized Balance Sheet Information for Equity Method Investments (Details) - USD ($) $ in Thousands		Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021
Current assets		$ 1,592,726	$ 1,827,399	$ 1,450,741
Total assets		2,282,141	2,494,927	2,373,684
Current liabilities		939,254	1,069,318	1,000,135
Granite’s share of net assets		22,987	23,368	27,760
Equity Method Investment, Nonconsolidated Investee or Group of Investees [Member]
Current assets		34,389	34,374	29,912
Noncurrent assets		72,589	78,829	72,388
Total assets		106,978	113,203	102,300
Current liabilities		18,414	23,685	13,652
Long-term liabilities	[1]	35,687	48,104	31,302
Total liabilities		54,101	71,789	44,954
Net assets		52,877	41,414	57,346
Granite’s share of net assets		$ 22,987	$ 23,368	$ 27,760

[1] This balance is primarily related to local bank debt for equipment purchases and debt associated with our real estate investments.