Regulatory Capital Requirements (Tables)

12 Months Ended

Dec. 31, 2011

Regulatory Capital Requirements [Abstract]

Schedule of compliance with Regulatory Compliance Requirements under Banking Regulations

The Company and NBT Bank's actual capital amounts and ratios are presented as follows:

	Actual					Regulatory ratio requirements
(Dollars in thousands)	Amount		Ratio			Minimum capital adequacy			For classification as well capitalized
As of December 31, 2011
Total Capital (to risk weighted assets):
Company	$	528,674		12.81	%		8.00	%		10.00	%
NBT Bank		506,246		12.28	%		8.00	%		10.00	%
Tier I Capital (to risk weighted assets)
Company		476,837		11.56	%		4.00	%		6.00	%
NBT Bank		454,476		11.03	%		4.00	%		6.00	%
Tier I Capital (to average assets)
Company		476,837		8.74	%		4.00	%		5.00	%
NBT Bank		454,476		8.35	%		4.00	%		5.00	%
As of December 31, 2010
Total Capital (to risk weighted assets):
Company	$	537,305		13.70	%		8.00	%		10.00	%
NBT Bank		510,196		13.03	%		8.00	%		10.00	%
Tier I Capital (to risk weighted assets)
Company		487,994		12.44	%		4.00	%		6.00	%
NBT Bank		460,969		11.77	%		4.00	%		6.00	%
Tier I Capital (to average assets)
Company		487,994		9.16	%		4.00	%		5.00	%
NBT Bank		460,969		8.67	%		4.00	%		5.00	%