Repurchase Agreements (Detail) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Advances from Federal Home Loan Banks, Total	$ 12,157	$ 5,691
U S Government Agencies Debt Securities [Member]
Advances from Federal Home Loan Banks, Total	11,287	1,622
U S States and Political Subdivisions [Member]
Advances from Federal Home Loan Banks, Total	870	4,069
Maturity Overnight [Member]
Advances from Federal Home Loan Banks, Total	12,157	5,691
Maturity Overnight [Member] | U S Government Agencies Debt Securities [Member]
Advances from Federal Home Loan Banks, Total	11,287	1,622
Maturity Overnight [Member] | U S States and Political Subdivisions [Member]
Advances from Federal Home Loan Banks, Total	870	4,069
Maturity Less than 30 Days [Member]
Advances from Federal Home Loan Banks, Total	0	0
Maturity Less than 30 Days [Member] | U S Government Agencies Debt Securities [Member]
Advances from Federal Home Loan Banks, Total	0	0
Maturity Less than 30 Days [Member] | U S States and Political Subdivisions [Member]
Advances from Federal Home Loan Banks, Total	0	0
Maturity 30 to 90 Days [Member]
Advances from Federal Home Loan Banks, Total	0	0
Maturity 30 to 90 Days [Member] | U S Government Agencies Debt Securities [Member]
Advances from Federal Home Loan Banks, Total	0	0
Maturity 30 to 90 Days [Member] | U S States and Political Subdivisions [Member]
Advances from Federal Home Loan Banks, Total	0	0
Maturity Greater than 90 Days [Member]
Advances from Federal Home Loan Banks, Total	0	0
Maturity Greater than 90 Days [Member] | U S Government Agencies Debt Securities [Member]
Advances from Federal Home Loan Banks, Total	0	0
Maturity Greater than 90 Days [Member] | U S States and Political Subdivisions [Member]
Advances from Federal Home Loan Banks, Total	$ 0	$ 0