Regulatory Capital - Summary of Regulatory Capital Requirement (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total capital (to risk-weighted assets), Actual, Amount	$ 648,804	$ 548,364
Total capital (to risk-weighted assets), Actual, Ratio	14.91%	13.95%
Total capital (to risk-weighted assets), For capital adequacy purposes, Amount	$ 348,024	$ 314,395
Total capital (to risk-weighted assets), For capital adequacy purposes, Ratio	8.00%	8.00%
Total capital (to risk-weighted assets), Required for capital1 adequacy purposes with capital buffer, Amount	$ 456,782	$ 412,644
Total capital (to risk-weighted assets), Required for capital1 adequacy purposes with capital buffer, Ratio	10.50%	10.50%
Tier 1 capital (to average assets), Actual, Amount	$ 607,340	$ 530,643
Tier 1 capital (to average assets), Actual, Ratio	13.96%	13.50%
Tier 1 capital (to average assets), For capital adequacy purposes, Amount	$ 261,018	$ 235,796
Tier 1 capital (to average assets), For capital adequacy purpose, Ratio	6.00%	6.00%
Tier 1 capital (to average assets), Required for capital1 adequacy purposes with capital buffer, Amount	$ 369,775	$ 334,044
Tier 1 capital (to average assets), Required for capital1 adequacy purposes with capital buffer, Ratio	8.50%	8.50%
Common equity tier 1 capital, Actual Amount	$ 491,281	$ 473,150
Common equity tier 1 capital, Actual Ratio	11.29%	12.04%
Common equity tier 1 capital, For capital adequacy purposes, Amount	$ 195,764	$ 176,846
Common equity tier 1 capital, For capital adequacy purpose, Ratio	4.50%	4.50%
Common equity tier 1 capital (to risk-weighted assets), Required for capital1 adequacy purposes with capital buffer, Amount	$ 304,522	$ 275,094
Common equity tier 1 capital (to risk-weighted assets), Required for capital1 adequacy purposes with capital buffer, Ratio	7.00%	7.50%
Tier 1 capital (to average assets), Actual, Amount	$ 607,340	$ 530,643
Tier 1 capital (to average assets), Actual, Ratio	10.68%	10.50%
Tier 1 capital (to average assets), For capital adequacy purposes, Amount	$ 227,507	$ 202,111
Tier 1 capital (to average assets), For capital adequacy purpose, Ratio	4.00%	4.00%
Tier 1 capital (to average assets), Required for capital1 adequacy purposes with capital buffer, Amount	$ 227,507	$ 202,111
Tier 1 capital (to average assets), Required for capital1 adequacy purposes with capital buffer, Ratio	4.00%	4.00%
Bank
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total capital (to risk-weighted assets), Actual, Amount	$ 532,315	$ 497,227
Total capital (to risk-weighted assets), Actual, Ratio	12.21%	12.65%
Total capital (to risk-weighted assets), For capital adequacy purposes, Amount	$ 348,810	$ 314,452
Total capital (to risk-weighted assets), For capital adequacy purposes, Ratio	8.00%	8.00%
Total capital (to risk-weighted assets), Required for capital1 adequacy purposes with capital buffer, Amount	$ 457,813	$ 412,718
Total capital (to risk-weighted assets), Required for capital1 adequacy purposes with capital buffer, Ratio	10.50%	10.50%
Total capital (to risk-weighted assets), For well capitalized purpose, Amount	$ 436,013	$ 393,065
Total capital (to risk-weighted assets), For well capitalized purpose, Ratio	10.00%	10.00%
Tier 1 capital (to average assets), Actual, Amount	$ 492,221	$ 479,506
Tier 1 capital (to average assets), Actual, Ratio	11.29%	12.20%
Tier 1 capital (to average assets), For capital adequacy purposes, Amount	$ 261,606	$ 235,823
Tier 1 capital (to average assets), For capital adequacy purpose, Ratio	6.00%	6.00%
Tier 1 capital (to average assets), Required for capital1 adequacy purposes with capital buffer, Amount	$ 370,609	$ 334,082
Tier 1 capital (to average assets), Required for capital1 adequacy purposes with capital buffer, Ratio	8.50%	8.50%
Tier 1 capital (to average assets), For well capitalized purpose, Amount	$ 348,808	$ 314,430
Tier 1 capital (to average assets), For well capitalized purposes, Ratio	8.00%	8.00%
Common equity tier 1 capital, Actual Amount	$ 492,221	$ 479,506
Common equity tier 1 capital, Actual Ratio	11.29%	12.20%
Common equity tier 1 capital, For capital adequacy purposes, Amount	$ 196,205	$ 176,867
Common equity tier 1 capital, For capital adequacy purpose, Ratio	4.50%	4.50%
Common equity tier 1 capital (to risk-weighted assets), Required for capital1 adequacy purposes with capital buffer, Amount	$ 305,207	$ 275,126
Common equity tier 1 capital (to risk-weighted assets), Required for capital1 adequacy purposes with capital buffer, Ratio	7.00%	7.50%
Common equity tier 1 capital, For well capitalized purpose, Amount	$ 283,407	$ 255,475
Common equity tier 1 capital, For well capitalized purposes, Ratio	6.50%	6.50%
Tier 1 capital (to average assets), Actual, Amount	$ 492,221	$ 479,506
Tier 1 capital (to average assets), Actual, Ratio	8.71%	9.49%
Tier 1 capital (to average assets), For capital adequacy purposes, Amount	$ 226,158	$ 202,110
Tier 1 capital (to average assets), For capital adequacy purpose, Ratio	4.00%	4.00%
Tier 1 capital (to average assets), Required for capital1 adequacy purposes with capital buffer, Amount	$ 226,158	$ 202,110
Tier 1 capital (to average assets), Required for capital1 adequacy purposes with capital buffer, Ratio	4.00%	4.00%
Tier 1 capital (to average assets), For well capitalized purpose, Amount	$ 282,697	$ 252,638
Tier 1 capital (to average assets), For well capitalized purposes, Ratio	5.00%	5.00%