| Amount of investments in debt securities expected to be converted to cash, sold or exchanged within one year or the normal operating cycle, if longer. | en-US | http://www.xbrl.org/2003/role/documentation | http://www.xbrl.org/2003/role/link |
| Marketable Securities, Fixed Maturities, Current (Deprecated 2018-01-31) | en-US | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| Marketable Securities, Fixed Maturities, Current, Total (Deprecated 2018-01-31) | en-US | http://www.xbrl.org/2003/role/totalLabel | http://www.xbrl.org/2003/role/link |