- DefinitionPeriod between issuance and maturity of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.
Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
 -Topic 820
 -SubTopic 10
 -Name Accounting Standards Codification
 -Section 50
 -Paragraph 2
 -Subparagraph (bbb)(2)(i)
 -Publisher FASB
 -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2
Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
 -Topic 820
 -SubTopic 10
 -Name Accounting Standards Codification
 -Section 50
 -Paragraph 2
 -Subparagraph (bbb)(2)
 -Publisher FASB
 -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2
Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
 -Topic 820
 -SubTopic 10
 -Name Accounting Standards Codification
 -Section 50
 -Paragraph 2
 -Subparagraph (bbb)(1)
 -Publisher FASB
 -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2
| Name: | us-gaap_DebtSecuritiesAvailableForSaleTerm | 
| Namespace Prefix: | us-gaap_ | 
| Data Type: | xbrli:durationItemType | 
| Balance Type: | na | 
| Period Type: | instant |