Assets Measured at Fair Value on Recurring Basis (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Securities available for sale, at fair value	$ 99,111	$ 147,909
Loans held for sale	138,301	41,990
Total assets measured at fair value on a recurring basis	237,412
Mortgage-backed securities issued by U.S. Agencies
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Securities available for sale, at fair value	91,339
Municipal securities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Securities available for sale, at fair value	470
Collateralized mortgage obligations issued by non-agency
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Securities available for sale, at fair value	2,640
Asset backed securities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Securities available for sale, at fair value	237
Mutual funds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Securities available for sale, at fair value	4,425
Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Securities available for sale, at fair value	4,425
Total assets measured at fair value on a recurring basis	4,425
Level 1 | Mutual funds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Securities available for sale, at fair value	4,425
Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Securities available for sale, at fair value	94,449
Loans held for sale	138,301
Total assets measured at fair value on a recurring basis	232,750
Level 2 | Mortgage-backed securities issued by U.S. Agencies
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Securities available for sale, at fair value	91,339
Level 2 | Municipal securities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Securities available for sale, at fair value	470
Level 2 | Collateralized mortgage obligations issued by non-agency
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Securities available for sale, at fair value	2,640
Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Securities available for sale, at fair value	237
Total assets measured at fair value on a recurring basis	237
Level 3 | Asset backed securities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Securities available for sale, at fair value	$ 237