Fair Value of Financial Instruments - Fair Value Measured on a Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Securities available for sale, fair value	$ 647,974	$ 772,500
us-gaap_FairValueAssetsLevel2ToLevel1TransfersAmount	0	0
Collateralized Mortgage Backed Securities [Member]
Securities available for sale, fair value	404,460	523,849
Other Securities [Member]
Securities available for sale, fair value	1,295	1,332
Fair Value, Measurements, Recurring [Member]
Total assets	649,293	774,852
Financial and Nonfinancial Liabilities, Fair Value Disclosure	104,123	64,037
Fair Value, Measurements, Recurring [Member] \| Collateralized Mortgage Backed Securities [Member]
Securities available for sale, fair value	404,460	523,849
Fair Value, Measurements, Recurring [Member] \| Other Securities [Member]
Securities available for sale, fair value	243,514	248,651
Fair Value, Measurements, Recurring [Member] \| Interest Rate Swap [Member]
Interest Rate Swaps, Net Amount	1,319	2,352
Interest Rate Swaps, Net Amount	60,987	19,653
Fair Value, Measurements, Recurring [Member] \| Junior Subordinated Debentures [Member]
Borrowings	43,136	44,384
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member]
Total assets	12,703	12,216
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member] \| Other Securities [Member]
Securities available for sale, fair value	12,703	12,216
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member]
Total assets	635,295	761,304
Financial and Nonfinancial Liabilities, Fair Value Disclosure	60,987	19,653
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member] \| Collateralized Mortgage Backed Securities [Member]
Securities available for sale, fair value	404,460	523,849
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member] \| Other Securities [Member]
Securities available for sale, fair value	229,516	235,103
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member] \| Interest Rate Swap [Member]
Interest Rate Swaps, Net Amount	1,319	2,352
Interest Rate Swaps, Net Amount	60,987	19,653
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 3 [Member]
Total assets	1,295	1,332
Financial and Nonfinancial Liabilities, Fair Value Disclosure	43,136	44,384
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 3 [Member] \| Other Securities [Member]
Securities available for sale, fair value	1,295	1,332
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 3 [Member] \| Junior Subordinated Debentures [Member]
Borrowings	43,136	44,384
Fair Value, Measurements, Nonrecurring [Member]
Total assets	11,980	1,320
Financial and Nonfinancial Liabilities, Fair Value Disclosure	0	0
Fair Value, Assets, Level 1 to Level 2 Transfers, Amount	0	0
Fair Value, Measurements, Nonrecurring [Member] \| Fair Value, Inputs, Level 3 [Member]
Total assets	$ 11,980	$ 1,320

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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Fair value of financial and nonfinancial obligations.

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