Loans - Summary of TDRs (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Financing Receivable, Modifications [Line Items]
Total TDRs	$ 79,793	$ 93,066
Commercial loan portfolio
Financing Receivable, Modifications [Line Items]
Total TDRs	60,228	70,785
Consumer loan portfolio
Financing Receivable, Modifications [Line Items]
Total TDRs	19,565	22,281
Accruing TDRs
Financing Receivable, Modifications [Line Items]
Total TDRs	55,789	62,535
Accruing TDRs | Commercial loan portfolio
Financing Receivable, Modifications [Line Items]
Total TDRs	40,886	45,388
Accruing TDRs | Consumer loan portfolio
Financing Receivable, Modifications [Line Items]
Total TDRs	14,903	17,147
Nonaccrual TDRs
Financing Receivable, Modifications [Line Items]
Total TDRs	24,004	30,531
Nonaccrual TDRs | Commercial loan portfolio
Financing Receivable, Modifications [Line Items]
Total TDRs	19,342	25,397
Nonaccrual TDRs | Consumer loan portfolio
Financing Receivable, Modifications [Line Items]
Total TDRs	$ 4,662	$ 5,134