| SourceName | Premium Amortization on Purchased Callable Debt Securities | http://fasb.org/srt/role/changeNote/changeNote |
| TaxonomyVersion | 2018 | http://fasb.org/srt/role/changeNote/changeNote |
| ChangeDate | 2017-04 | http://fasb.org/srt/role/changeNote/changeNote |
| NewElement | true | http://fasb.org/srt/role/changeNote/changeNote |
| Source_ASU_Number | 2017-08 | http://fasb.org/srt/role/changeNote/changeNote |
| Publisher | FASB | http://www.xbrl.org/2003/role/disclosureRef |
| Name | Accounting Standards Codification | http://www.xbrl.org/2003/role/disclosureRef |
| Topic | 310 | http://www.xbrl.org/2003/role/disclosureRef |
| SubTopic | 20 | http://www.xbrl.org/2003/role/disclosureRef |
| Section | 65 | http://www.xbrl.org/2003/role/disclosureRef |
| Paragraph | 1 | http://www.xbrl.org/2003/role/disclosureRef |
| URI | http://asc.fasb.org/extlink&oid=109123552&loc=SL109123557-218513 | http://www.xbrl.org/2003/role/disclosureRef |