v3.26.1
Regulatory Capital Requirements (Details)
$ in Thousands
Jun. 30, 2026
USD ($)
Dec. 31, 2025
USD ($)
Total Capital (to Risk-Weighted Assets)    
Total Capital (to Risk-Weighted Assets), Actual Amount $ 867,074 $ 871,043
Total Capital (to Risk-Weighted Assets), Actual Ratio 0.128 0.136
Total Capital (to Risk-Weighted Assets), For minimum capital adequacy purposes, Amount $ 543,588 $ 512,904
Total Capital (to Risk-Weighted Assets), For minimum capital adequacy purposes, Ratio 0.08 0.08
Total Capital (to Risk-Weighted Assets), To be well capitalized under prompt corrective action provisions, Amount $ 679,485 $ 641,130
Total Capital (to Risk-Weighted Assets), To be well capitalized under prompt corrective action provisions, Ratio 0.10 0.10
Tier I Capital (to Risk-Weighted Assets)    
Tier I Capital (to Risk-Weighted Assets), Actual Amount $ 811,941 $ 822,626
Tier I Capital (to Risk-Weighted Assets), Actual Ratio 0.119 0.128
Tier I Capital (to Risk-Weighted Assets), For minimum capital adequacy purposes, Amount $ 407,691 $ 384,678
Tier I Capital (to Risk-Weighted Assets), For minimum capital adequacy purposes, Ratio 0.06 0.06
Tier I Capital (to Risk-Weighted Assets), To be well capitalized under prompt corrective action provisions, Amount $ 543,588 $ 512,904
Tier I Capital (to Risk-Weighted Assets), To be well capitalized under prompt corrective action provisions, Ratio 0.08 0.08
Common Equity Tier I Capital (to Risk-Weighted Assets)    
Common Equity Tier I Capital (to Risk-Weighted Assets), Actual Amount $ 811,941 $ 822,626
Common Equity Tier I Capital (to Risk-Weighted Assets), Actual Ratio 0.119 0.128
Common Equity Tier I Capital (to Risk-Weighted Assets), For minimum capital adequacy purposes, Amount $ 305,768 $ 288,508
Common Equity Tier I Capital (to Risk-Weighted Assets), For minimum capital adequacy purposes, Ratio 0.045 0.045
Common Equity Tier I Capital (to Risk-Weighted Assets), To be well capitalized under prompt corrective action provisions, Amount $ 441,665 $ 416,734
Common Equity Tier I Capital (to Risk-Weighted Assets), To be well capitalized under prompt corrective action provisions, Ratio 0.065 0.065
Tier I Capital (to Total Average Assets)    
Tier I Capital (to Total Average Assets), Actual Amount $ 811,941 $ 822,626
Tier I Capital (to Total Average Assets), Actual Ratio 0.113 0.133
Tier I Capital (to Total Average Assets), For minimum capital adequacy purposes, Amount $ 288,343 $ 247,709
Tier I Capital (to Total Average Assets), For minimum capital adequacy purposes, Ratio 0.04 0.04
Tier I Capital (to Total Average Assets), To be well capitalized under prompt corrective action provisions, Amount $ 360,429 $ 309,636
Tier I Capital (to Total Average Assets), To be well capitalized under prompt corrective action provisions, Ratio 0.05 0.05
Needham Bank    
Total Capital (to Risk-Weighted Assets)    
Total Capital (to Risk-Weighted Assets), Actual Amount $ 835,700 $ 791,298
Total Capital (to Risk-Weighted Assets), Actual Ratio 0.123 0.124
Total Capital (to Risk-Weighted Assets), For minimum capital adequacy purposes, Amount $ 542,889 $ 511,589
Total Capital (to Risk-Weighted Assets), For minimum capital adequacy purposes, Ratio 0.08 0.08
Total Capital (to Risk-Weighted Assets), To be well capitalized under prompt corrective action provisions, Amount $ 678,611 $ 639,486
Total Capital (to Risk-Weighted Assets), To be well capitalized under prompt corrective action provisions, Ratio 0.10 0.10
Tier I Capital (to Risk-Weighted Assets)    
Tier I Capital (to Risk-Weighted Assets), Actual Amount $ 780,567 $ 742,881
Tier I Capital (to Risk-Weighted Assets), Actual Ratio 0.115 0.116
Tier I Capital (to Risk-Weighted Assets), For minimum capital adequacy purposes, Amount $ 407,167 $ 383,692
Tier I Capital (to Risk-Weighted Assets), For minimum capital adequacy purposes, Ratio 0.06 0.06
Tier I Capital (to Risk-Weighted Assets), To be well capitalized under prompt corrective action provisions, Amount $ 542,889 $ 511,589
Tier I Capital (to Risk-Weighted Assets), To be well capitalized under prompt corrective action provisions, Ratio 0.08 0.08
Common Equity Tier I Capital (to Risk-Weighted Assets)    
Common Equity Tier I Capital (to Risk-Weighted Assets), Actual Amount $ 780,567 $ 742,881
Common Equity Tier I Capital (to Risk-Weighted Assets), Actual Ratio 0.115 0.116
Common Equity Tier I Capital (to Risk-Weighted Assets), For minimum capital adequacy purposes, Amount $ 305,375 $ 287,769
Common Equity Tier I Capital (to Risk-Weighted Assets), For minimum capital adequacy purposes, Ratio 0.045 0.045
Common Equity Tier I Capital (to Risk-Weighted Assets), To be well capitalized under prompt corrective action provisions, Amount $ 441,097 $ 415,666
Common Equity Tier I Capital (to Risk-Weighted Assets), To be well capitalized under prompt corrective action provisions, Ratio 0.065 0.065
Tier I Capital (to Total Average Assets)    
Tier I Capital (to Total Average Assets), Actual Amount $ 780,567 $ 742,881
Tier I Capital (to Total Average Assets), Actual Ratio 0.109 0.122
Tier I Capital (to Total Average Assets), For minimum capital adequacy purposes, Amount $ 286,834 $ 244,395
Tier I Capital (to Total Average Assets), For minimum capital adequacy purposes, Ratio 0.04 0.04
Tier I Capital (to Total Average Assets), To be well capitalized under prompt corrective action provisions, Amount $ 358,543 $ 305,494
Tier I Capital (to Total Average Assets), To be well capitalized under prompt corrective action provisions, Ratio 0.05 0.05