Securities - Summary of Amortized Cost and Fair Value of Debt Securities (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013
Available-for-sale:
Due in one year or less, Amortized cost	$ 279
Due after one through five years, Amortized cost	16,589
Due after five through ten years, Amortized cost	26,318
Due after ten years, Amortized cost	58,924
Total debt securities available-for-sale, Amortized cost	102,110
Due in one year or less, Fair value	280
Due after one through five years, Fair value	16,812
Due after five through ten years, Fair value	25,955
Due after ten years, Fair value	59,285
Total debt securities available-for-sale, Fair value	102,332
Held-to-maturity:
Due in one year or less, Amortized cost
Due after one through five years, Amortized cost
Due after five through ten years, Amortized cost	3,710
Due after ten years, Amortized cost	33,098
Total debt securities held-to-maturity, Amortized cost	36,808
Due in one year or less, Fair value
Due after one through five years, Fair value
Due after five through ten years, Fair value	3,655
Due after ten years, Fair value	32,035
Fair value, Held to maturity	$ 35,690