Loans - Summary of TDRs (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Financing Receivable, Modifications [Line Items]
Total TDRs	$ 73,596	$ 77,888
Commercial loan portfolio
Financing Receivable, Modifications [Line Items]
Total TDRs	55,700	58,842
Consumer loan portfolio
Financing Receivable, Modifications [Line Items]
Total TDRs	17,896	19,046
Accruing TDRs
Financing Receivable, Modifications [Line Items]
Total TDRs	48,266	48,782
Accruing TDRs | Commercial loan portfolio
Financing Receivable, Modifications [Line Items]
Total TDRs	34,161	34,484
Accruing TDRs | Consumer loan portfolio
Financing Receivable, Modifications [Line Items]
Total TDRs	14,105	14,298
Nonaccrual TDRs
Financing Receivable, Modifications [Line Items]
Total TDRs	25,330	29,106
Nonaccrual TDRs | Commercial loan portfolio
Financing Receivable, Modifications [Line Items]
Total TDRs	21,539	24,358
Nonaccrual TDRs | Consumer loan portfolio
Financing Receivable, Modifications [Line Items]
Total TDRs	$ 3,791	$ 4,748