| **Investment Securities - Gross Gains and Losses on Sales and Redemptions of Available for Sale Securities and Other Than Temporary Impairment Losses Recognized (Details) (USD $)In Thousands, unless otherwise specified** | 3 Months Ended | 9 Months Ended |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------|----------------|
||
| **Sales and Redemptions of Available for Sale Securities:**                                                                                                                                                                  |           |           |   |   |
| Gross gains                                                                                                                                                                                                                  | $ 0            | $ 843          | $ 487 | $ 2,134 |
| Gross losses                                                                                                                                                                                                                 | 0              | 0              | 0 | 0 |
| Other-than-temporary impairment losses                                                                                                                                                                                       | $ 0            | $ 0            | $ 0 | $ 0 |

| X                                                                                                                                                                                              |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_AvailableForSaleSecuritiesGrossRealizedGainLossNetAbstract**Namespace Prefix:**us-gaap_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
This item represents the gross profit realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 9 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27357-111563
+ Details**Name:**us-gaap_AvailableForSaleSecuritiesGrossRealizedGains**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
This item represents the gross loss realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 9 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27357-111563
+ Details**Name:**us-gaap_AvailableForSaleSecuritiesGrossRealizedLosses**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The amount of other than temporary impairment losses on investments in debt and equity securities categorized as Available-for-sale which have been recognized in earnings during the period. Such impairment losses consist of other than temporary impairments (OTTI) on equity securities, credit losses on investments in debt securities, and when the entity intends to sell an impaired debt security or it is more likely than not that the entity will be required to sell the impaired debt security before recovery of its amortized cost basis.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27161-111563
+ Details**Name:**us-gaap_OtherThanTemporaryImpairmentLossesInvestmentsPortionRecognizedInEarningsNetAvailableforsaleSecurities**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**duration |