| Debt Securities, Available-for-Sale, Weighted Average Yield, Maturity, after Year 5 Through 10 | en-US | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| Weighted average yield of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), maturing in sixth through tenth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach). | en-US | http://www.xbrl.org/2003/role/documentation | http://www.xbrl.org/2003/role/link |