Commitments and Contingent Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Minimum future rental payments:
2016	$ 6,774
2017	5,621
2018	4,983
2019	4,606
2020	3,810
Thereafter	13,968
Total minimum payments	39,762
Operating Leases, Rent Expense, Sublease Rentals	1,100	$ 756	$ 673
Operating Leases, Rent Expense, Net	7,400	8,300	$ 8,500
Commitments to Extend Credit [Member]
Minimum future rental payments:
Fair Value Disclosure, Off-balance Sheet Risks, Amount, Liability	1,930,000	1,580,000
Standby Letters of Credit [Member]
Minimum future rental payments:
Fair Value Disclosure, Off-balance Sheet Risks, Amount, Liability	38,700	36,700
Commercial Letter of Credit and other off-balance sheet liabilities [Member]
Minimum future rental payments:
Fair Value Disclosure, Off-balance Sheet Risks, Amount, Liability	$ 5,000	$ 0