v3.26.1
Summary of Significant Accounting Policies - Summary of Bank's Actual Capital Amounts and Ratios, and the Regulatory Minimum Ratios (Detail)
$ in Thousands
 3 Months Ended 12 Months Ended
Mar. 31, 2026
USD ($)
Dec. 31, 2025
USD ($)
Accounting Policies [Abstract]    
Regulatory, Minimum, Leverage ratio [1] 0.04  
Regulatory, Minimum, Common equity tier 1 capital ratio [2] 4.50%  
Regulatory, Minimum, tier 1 Buffer capital ratio [3] 6.00%  
Regulatory, Minimum, Total capital ratio [3] 0.08  
Regulatory, Well-Capitalized, Leverage ratio [1] 0.05  
Regulatory, Well-Capitalized, Common equity tier 1 capital ratio [2] 6.50%  
Regulatory, Well-Capitalized, tier 1 capital ratio [3] 0.08  
Regulatory, Well-Capitalized, Total capital ratio [3] 0.10  
Common equity Tier 1 capital $ 347,627 $ 356,038
Tier 1 capital 447,056 455,467
Total capital 479,609 487,292
Average assets 2,572,371 2,558,754
Risk-weighted assets $ 2,529,775 $ 2,472,328
Leverage ratio [1] 0.174 0.178
Common equity tier 1 capital ratio [2] 0.137 0.144
Tier 1 capital ratio [3] 0.177 0.184
Total capital ratio [3] 0.19 0.197
[1] Calculated by dividing Tier 1 capital by average assets.
[2] Calculated by subtracting preferred stock or non-controlling interest from Tier 1 capital and dividing by risk-weighted assets.
[3] Calculated by dividing Tier 1 or total capital by risk-weighted assets.