XML 104 R90.htm IDEA: XBRL DOCUMENT v3.20.4
Regulatory Capital Requirements (Details)
$ in Thousands
12 Months Ended
Dec. 31, 2020
USD ($)
Dec. 31, 2019
USD ($)
Tier I Capital (to average assets) [Abstract]    
Tier I capital to average assets $ 1,018,320 $ 963,147
Tier I capital to average assets ratio 0.0956 0.1033
Minimum Tier I leverage capital required for capital adequacy to average assets 0.0400 0.0400
Tier I leverage capital required for classification as well capitalized to average assets 0.0500 0.0500
Common Equity Tier I Capital [Abstract]    
Common equity Tier I capital $ 921,320 $ 866,147
Common equity Tier I capital ratio 0.1184 0.1129
Minimum Tier I capital required for capital adequacy 0.0450 0.0450
Minimum Tier I capital required for capital adequacy plus buffer 0.0700 0.0700
Tier I capital required for classification as well capitalized 0.0650 0.0650
Tier I Capital (to risk weighted assets) [Abstract]    
Tier I capital to risk weighted assets $ 1,018,320 $ 963,147
Tier I capital to risk weighted assets ratio 0.1309 0.1256
Minimum Tier I capital required for capital adequacy to risk weighted assets 0.0600 0.0600
Minimum Tier I capital required for capital adequacy plus buffer to risk weighted assets 0.0850 0.0850
Tier I capital required for classification as well capitalized to risk weighted assets 0.0800 0.0800
Total Capital (to risk weighted assets) [Abstract]    
Total capital to risk weighted assets $ 1,215,672 $ 1,037,041
Total capital to risk weighted assets ratio 0.1562 0.1352
Minimum capital required for capital adequacy to risk weighted assets 0.0800 0.0800
Total capital required for capital adequacy plus buffer to average assets 0.1050 0.1050
Capital required for classification as well capitalized to risk weighted assets 0.1000 0.1000
Permissible capital transition relief period 5 years  
NBT Bank [Member]    
Tier I Capital (to average assets) [Abstract]    
Tier I capital to average assets $ 1,054,097 $ 894,407
Tier I capital to average assets ratio 0.0995 0.0964
Minimum Tier I leverage capital required for capital adequacy to average assets 0.0400 0.0400
Tier I leverage capital required for classification as well capitalized to average assets 0.0500 0.0500
Common Equity Tier I Capital [Abstract]    
Common equity Tier I capital $ 1,054,097 $ 894,407
Common equity Tier I capital ratio 0.1367 0.1176
Minimum Tier I capital required for capital adequacy 0.0450 0.0450
Minimum Tier I capital required for capital adequacy plus buffer 0.0700 0.0700
Tier I capital required for classification as well capitalized 0.0650 0.0650
Tier I Capital (to risk weighted assets) [Abstract]    
Tier I capital to risk weighted assets $ 1,054,097 $ 894,407
Tier I capital to risk weighted assets ratio 0.1367 0.1176
Minimum Tier I capital required for capital adequacy to risk weighted assets 0.0600 0.0600
Minimum Tier I capital required for capital adequacy plus buffer to risk weighted assets 0.0850 0.0850
Tier I capital required for classification as well capitalized to risk weighted assets 0.0800 0.0800
Total Capital (to risk weighted assets) [Abstract]    
Total capital to risk weighted assets $ 1,150,544 $ 968,301
Total capital to risk weighted assets ratio 0.1493 0.1273
Minimum capital required for capital adequacy to risk weighted assets 0.0800 0.0800
Total capital required for capital adequacy plus buffer to average assets 0.1050 0.1050
Capital required for classification as well capitalized to risk weighted assets 0.1000 0.1000