| Standard label: | Auction Market Preferred Securities, Stock, Shares Outstanding, Period Increase (Decrease) |
| Name: | us-gaap:AuctionMarketPreferredSecuritiesStockSharesOutstandingPeriodIncreaseDecrease |
| Documentation: | The increase (decrease) in the number of Auction Market Preferred Securities during the period being reported. |
| Object type: | cm:Concept |
| Data type: | Shares (xbrli:sharesItemType) |
| Period type: | For Period (duration) |
| Balance type: | (no balance type) |
| Abstract: | false |
| Workiva Wdesk Taxonomy Analyzer: | us-gaap:AuctionMarketPreferredSecuritiesStockSharesOutstandingPeriodIncreaseDecrease |
| Label | Role | Language |
| Auction Market Preferred Securities, Stock, Shares Outstanding, Period Increase (Decrease) | http://www.xbrl.org/2003/role/label | en-US |
| Auction Market Preferred Securities, Stock, Shares Outstanding, Period Increase (Decrease), Total | http://www.xbrl.org/2003/role/totalLabel | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 210 10 S99 1 (SX 210.5-02.28) | http://fasb.org/us-gaap/role/ref/legacyRef | 210 |
| FASB Accounting Standards Codification 505 10 S99 1 (SX 210.3-04) | http://fasb.org/us-gaap/role/ref/legacyRef | 505 |