Financial Instruments with Off-Balance Sheet Risk and Derivatives (Company's Interest Rate Swaps) (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Pay Fixed/Receive Variable Swaps
Derivative [Line Items]
Notional Amount	$ 10,425,000	$ 23,200,000
Estimated Fair Value	(1,501,000)	(1,608,000)
Years to Maturity	8 years 6 months	4 years 7 months 6 days
Receive Rate	2.53%	3.30%
Pay Rate	5.31%	5.03%
Pay Variable/Receive Fixed Swaps
Derivative [Line Items]
Notional Amount	10,425,000	23,200,000
Estimated Fair Value	1,501,000	1,608,000
Years to Maturity	8 years 6 months	4 years 7 months 6 days
Receive Rate	5.31%	5.03%
Pay Rate	2.53%	3.30%
Swap
Derivative [Line Items]
Notional Amount	20,850,000	46,400,000
Estimated Fair Value	$ 0	$ 0
Years to Maturity	8 years 6 months	4 years 7 months 6 days
Receive Rate	3.92%	4.17%
Pay Rate	3.92%	4.17%