Amount of life insurance in-force assumed from other companies as of the balance sheet date for the domestic life insurance companies.

No definition available.

Name:	gnw_LifeInsuranceInForceAssumedFromOtherCompanies
Namespace Prefix:	gnw_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Amount of life insurance in-force ceded to other companies as of the balance sheet date for the domestic life insurance companies.

No definition available.

Name:	gnw_LifeInsuranceInForceCededToOtherCompanies
Namespace Prefix:	gnw_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Amount of direct life insurance in-force as of the balance sheet date for the domestic life insurance companies.

No definition available.

Name:	gnw_LifeInsuranceInForceDirect
Namespace Prefix:	gnw_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Net amount of life insurance in-force as of the balance sheet date for the domestic life insurance companies.

No definition available.

Name:	gnw_LifeInsuranceInForceNet
Namespace Prefix:	gnw_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Percentage of life insurance in-forced assumed to the net amount of insurance in-force for the domestic life insurance companies.

No definition available.

Name:	gnw_PercentageOfLifeInsuranceInForceAssumedToNet
Namespace Prefix:	gnw_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Name:	us-gaap_ReinsuranceDisclosuresAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration