Gross Unrealized Losses and Fair Values of Investments (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, Fair Value	$ 23,129
Less than 12 months, Unrealized Loss	(18)
12 months or more Fair Value	2,917
12 months or more, Unrealized Loss	(2,190)
Total Fair Value	26,046
Total Unrealized Loss	(2,208)
Mortgage-backed securities issued by U.S. Agencies
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, Fair Value	23,129
Less than 12 months, Unrealized Loss	(18)
12 months or more Fair Value	40
12 months or more, Unrealized Loss	(1)
Total Fair Value	23,169
Total Unrealized Loss	(19)
Collateralized mortgage obligations issued by non-agency
Schedule of Available-for-sale Securities [Line Items]
12 months or more Fair Value	2,640
12 months or more, Unrealized Loss	(179)
Total Fair Value	2,640
Total Unrealized Loss	(179)
Asset backed securities
Schedule of Available-for-sale Securities [Line Items]
12 months or more Fair Value	237
12 months or more, Unrealized Loss	(2,010)
Total Fair Value	237
Total Unrealized Loss	$ (2,010)