Securities - Securities Held to Maturity in Unrealized Loss Position (Detail) $ in Thousands	Jun. 30, 2015 USD ($)
Schedule Of Held To Maturity Securities [Line Items]
Fair value, Less than 12 months	$ 4,679
Unrealized loss, Less than 12 months	(96)
Total fair value	4,679
Total unrealized loss	(96)
States of the U.S. and Political Subdivisions [Member]
Schedule Of Held To Maturity Securities [Line Items]
Fair value, Less than 12 months	4,679
Unrealized loss, Less than 12 months	(96)
Total fair value	4,679
Total unrealized loss	$ (96)