| Name | DepositAssetsAmortizatonExpenseFromExpirations |
|---|---|
| Namespace | http://fasb.org/us-gaap/2020-01-31 |
| Prefix | us-gaap |
| Data type | xbrli:monetaryItemType |
| Period type | duration |
| Substitution Group | xbrli:item |
| Balance | debit |
| Nillable | True |
| Abstract | False |
| Text | Lang | Role | Container role |
|---|---|---|---|
| Amount of amortization expense from expiration of contracts underlying deposit assets. | en-US | http://www.xbrl.org/2003/role/documentation | http://www.xbrl.org/2003/role/link |
| Deposit Assets, Amortizaton Expense from Expirations | en-US | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| Name | Value | Role |
|---|---|---|
| Publisher | FASB | http://www.xbrl.org/2003/role/disclosureRef |
| Name | Accounting Standards Codification | http://www.xbrl.org/2003/role/disclosureRef |
| Topic | 340 | http://www.xbrl.org/2003/role/disclosureRef |
| SubTopic | 30 | http://www.xbrl.org/2003/role/disclosureRef |
| Section | 50 | http://www.xbrl.org/2003/role/disclosureRef |
| Paragraph | 2 | http://www.xbrl.org/2003/role/disclosureRef |
| Subparagraph | (c) | http://www.xbrl.org/2003/role/disclosureRef |
| URI | http://asc.fasb.org/extlink&oid=99397363&loc=d3e9432-108338 | http://www.xbrl.org/2003/role/disclosureRef |