Repurchase Agreements (Detail) $ in Thousands	Sep. 30, 2015 USD ($)
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement, Total	$ 12,006
US Government Corporations and Agencies Securities [Member]
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement, Total	10,503
U S States and Political Subdivisions [Member]
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement, Total	1,503
Maturity Overnight [Member]
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement, Total	12,006
Maturity Overnight [Member] | US Government Corporations and Agencies Securities [Member]
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement, Total	10,503
Maturity Overnight [Member] | U S States and Political Subdivisions [Member]
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement, Total	1,503
Maturity Less than 30 Days [Member]
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement, Total	0
Maturity Less than 30 Days [Member] | US Government Corporations and Agencies Securities [Member]
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement, Total	0
Maturity Less than 30 Days [Member] | U S States and Political Subdivisions [Member]
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement, Total	0
Maturity 30 to 90 Days [Member]
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement, Total	0
Maturity 30 to 90 Days [Member] | US Government Corporations and Agencies Securities [Member]
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement, Total	0
Maturity 30 to 90 Days [Member] | U S States and Political Subdivisions [Member]
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement, Total	0
Maturity Greater than 90 Days [Member]
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement, Total	0
Maturity Greater than 90 Days [Member] | US Government Corporations and Agencies Securities [Member]
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement, Total	0
Maturity Greater than 90 Days [Member] | U S States and Political Subdivisions [Member]
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement, Total	$ 0