Commitments and Contingent Liabilities (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Dec. 31, 2016	Aug. 24, 2016
Other Commitments [Line Items]
Sale Leaseback Transaction, Monthly Rental Payments	$ 12
Sale Leaseback Transaction, Deferred Gain, Gross			$ 742
Sale Leaseback Transaction, Deferred Gain, Net	679
Commitments to Extend Credit [Member]
Other Commitments [Line Items]
Fair Value Disclosure, Off-balance Sheet Risks, Amount, Liability	2,180,000	$ 2,170,000
Standby Letters of Credit [Member]
Other Commitments [Line Items]
Fair Value Disclosure, Off-balance Sheet Risks, Amount, Liability	49,600	49,700
Commercial Letter of Credit and other off-balance sheet liabilities [Member]
Other Commitments [Line Items]
Fair Value Disclosure, Off-balance Sheet Risks, Amount, Liability	$ 3,000	$ 3,400