Fair Value - Fair Value Measurements for Items Measured at Fair Value (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale (at fair value)	$ 946,855	$ 865,831
Loans held for sale	20,029	11,873
Other real estate owned	12,390	12,802
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale (at fair value)	946,855	865,831
Loans held for sale	20,029	11,873
Equity securities	6,392	6,205
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale (at fair value)	100	100
Loans held for sale	0	0
Equity securities	6,392	6,205
Fair Value, Measurements, Recurring | Significant Other Observable Inputs
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale (at fair value)	946,755	865,731
Loans held for sale	20,029	11,873
Equity securities	0	0
Fair Value, Measurements, Recurring | Significant Other Unobservable Inputs
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale (at fair value)	0	0
Loans held for sale	0	0
Equity securities	0	0
Fair Value, Measurements, Nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	5,123	8,590
Other real estate owned	12,390	12,802
Fair Value, Measurements, Nonrecurring | Quoted Prices in Active Markets for Identical Assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	0	0
Other real estate owned	0	0
Fair Value, Measurements, Nonrecurring | Significant Other Observable Inputs
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	1,419	2,290
Other real estate owned	241	297
Fair Value, Measurements, Nonrecurring | Significant Other Unobservable Inputs
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	3,704	6,300
Other real estate owned	$ 12,149	$ 12,505