| **Commitments and Contingent Liabilities (Details) (USD $)In Thousands, unless otherwise specified** | Dec. 31, 2014                                                                                                                                       | Dec. 31, 2013                                                                                                                                       |
|------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------|
| Loan commitments to extend credit                                                                    |                                                                                                                                                |                                                                                                                                                |
| **Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]**                         |                                                                                                                                                |                                                                                                                                                |
| Amounts of commitments                                                                               | $ 1,617,552us-gaap_FairValueDisclosureOffbalanceSheetRisksAmountLiability/ us-gaap_FinancialInstrumentAxis= us-gaap_CommitmentsToExtendCreditMember | $ 1,216,470us-gaap_FairValueDisclosureOffbalanceSheetRisksAmountLiability/ us-gaap_FinancialInstrumentAxis= us-gaap_CommitmentsToExtendCreditMember |
| Standby letters of credit                                                                            |                                                                                                                                                |                                                                                                                                                |
| **Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]**                         |                                                                                                                                                |                                                                                                                                                |
| Amounts of commitments                                                                               | $ 52,655us-gaap_FairValueDisclosureOffbalanceSheetRisksAmountLiability/ us-gaap_FinancialInstrumentAxis= us-gaap_StandbyLettersOfCreditMember       | $ 41,508us-gaap_FairValueDisclosureOffbalanceSheetRisksAmountLiability/ us-gaap_FinancialInstrumentAxis= us-gaap_StandbyLettersOfCreditMember       |

| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The fair value of financial liabilities, which are not recognized in the financial statements (off-balance sheet) because they fail to meet some other criterion for recognition.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 10 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=35750535&loc=d3e13433-108611
+ Details**Name:**us-gaap_FairValueDisclosureOffbalanceSheetRisksAmountLiability**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**instant |
| X                                                                                                                                                                                               |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_FairValueOffBalanceSheetRisksDisclosureInformationLineItems**Namespace Prefix:**us-gaap_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                               |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_FinancialInstrumentAxis=us-gaap_CommitmentsToExtendCreditMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                                            |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_FinancialInstrumentAxis=us-gaap_StandbyLettersOfCreditMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |