Financial Instruments with Off-Balance Sheet Risk (Details) $ in Thousands	Jun. 30, 2017 USD ($)
Entity Information [Line Items]
Credit Extension Commitments	$ 2,250,387
Credit Extension Commitments, Beyond One Year	874,134
Standby Letters of Credit
Entity Information [Line Items]
Credit Extension Commitments	54,241
Unused Credit Card Lines
Entity Information [Line Items]
Credit Extension Commitments	$ 673,280