Note 16 - Contingencies - Legal Proceedings (Details Textual) - USD ($) $ in Millions		3 Months Ended
Apr. 29, 2021	Mar. 31, 2021
Loss Contingency Accrual, Ending Balance		$ 66
Gain (Loss) Related to Litigation Settlement, Total		(66)
Police Retirement System of St. Louis v. Granite Construction Incorporated, et al. [Member]
Litigation Settlement, Amount Awarded to Other Party	$ 129
Loss Contingency, Receivable, Ending Balance	$ 63	63
Gain (Loss) Related to Litigation Settlement, Total		$ (66)

Amount of gain (loss) recognized in settlement of litigation and insurance claims. Excludes claims within an insurance entity's normal claims settlement process.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=121557415&loc=d3e14326-108349

+ Details

Name:	us-gaap_GainLossRelatedToLitigationSettlement
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount awarded to other party in judgment or settlement of litigation.

+ References

No definition available.

+ Details

Name:	us-gaap_LitigationSettlementAmountAwardedToOtherParty
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of loss contingency liability.

+ References

+ Details

Name:	us-gaap_LossContingencyAccrualAtCarryingValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of receivable related to a loss contingency accrual. For example, an insurance recovery receivable.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=121555522&loc=d3e12053-110248

+ Details

Name:	us-gaap_LossContingencyReceivable
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	srt_LitigationCaseAxis=gva_PoliceRetirementSystemOfStLouisVGraniteConstructionIncorporatedEtAlMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: