Loans - Summary of TDRs (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Financing Receivable, Modifications [Line Items]
Total TDRs	$ 75,465	$ 77,888
Commercial loan portfolio
Financing Receivable, Modifications [Line Items]
Total TDRs	57,130	58,842
Consumer loan portfolio
Financing Receivable, Modifications [Line Items]
Total TDRs	18,335	19,046
Accruing TDRs
Financing Receivable, Modifications [Line Items]
Total TDRs	49,286	48,782
Accruing TDRs | Commercial loan portfolio
Financing Receivable, Modifications [Line Items]
Total TDRs	35,216	34,484
Accruing TDRs | Consumer loan portfolio
Financing Receivable, Modifications [Line Items]
Total TDRs	14,070	14,298
Nonaccrual TDRs
Financing Receivable, Modifications [Line Items]
Total TDRs	26,179	29,106
Nonaccrual TDRs | Commercial loan portfolio
Financing Receivable, Modifications [Line Items]
Total TDRs	21,914	24,358
Nonaccrual TDRs | Consumer loan portfolio
Financing Receivable, Modifications [Line Items]
Total TDRs	$ 4,265	$ 4,748