| Standard label: | Payments for (Proceeds from) Held-to-maturity Securities, Short-term |
| Name: | us-gaap:PaymentsForProceedsFromHeldtomaturitySecuritiesShortterm |
| Documentation: | Amount of cash outflow (inflow) through acquisition (sale) of short-term held-to-maturity securities. |
| Object type: | cm:Concept |
| Data type: | Monetary (xbrli:monetaryItemType) |
| Period type: | For Period (duration) |
| Balance type: | Credit |
| Abstract: | false |
| Workiva Wdesk Taxonomy Analyzer: | us-gaap:PaymentsForProceedsFromHeldtomaturitySecuritiesShortterm |
| Label | Role | Language |
| Payments for (Proceeds from) Held-to-maturity Securities, Short-term | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 230 10 45 9 (a) | http://www.xbrl.org/2009/role/commonPracticeRef | 230 |
| FASB Accounting Standards Codification 230 10 45 12 (a) | http://www.xbrl.org/2009/role/commonPracticeRef | 230 |
| FASB Accounting Standards Codification 230 10 45 13 (a) | http://www.xbrl.org/2009/role/commonPracticeRef | 230 |