| Debt and Equity Securities, Gain (Loss), Excluding Other-than-temporary Impairment Loss | en-US | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| Debt and Equity Securities, Gain (Loss), Excluding Other-than-temporary Impairment Loss, Total | en-US | http://www.xbrl.org/2003/role/totalLabel | http://www.xbrl.org/2003/role/link |
| Amount of unrealized and realized gain (loss) on investment in debt and equity securities, excluding other-than-temporary impairment (OTTI). | en-US | http://www.xbrl.org/2003/role/documentation | http://www.xbrl.org/2003/role/link |