Securities - Summary of Amortized Cost and Estimated Fair Values of Securities Held for Investment (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	$ 9,297
Gross Unrealized Gains	89
Gross Unrealized Losses	0
Estimated Fair Value	9,386
Mortgage-backed securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	533
Gross Unrealized Gains	37
Gross Unrealized Losses	0
Estimated Fair Value	570
States and political subdivisions [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	8,764
Gross Unrealized Gains	52
Gross Unrealized Losses	0
Estimated Fair Value	$ 8,816