Securities with Gross Unrealized Losses in Continuous Loss Position (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Schedule of Available-for-sale Securities [Line Items]
Available for sale, Less Than Twelve Months Gross Unrealized Losses	$ (427)	$ (22)
Available for sale, Less Than Twelve Months Fair Value	61,912	14,652
Available for sale, Over Twelve Months Gross Unrealized Losses	(60)	(570)
Available for sale, Over twelve Months Fair Value	1,660	3,221
Government sponsored residential mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Available for sale, Less Than Twelve Months Gross Unrealized Losses	(166)	(22)
Available for sale, Less Than Twelve Months Fair Value	35,375	14,652
Corporate bonds
Schedule of Available-for-sale Securities [Line Items]
Available for sale, Less Than Twelve Months Gross Unrealized Losses	(260)
Available for sale, Less Than Twelve Months Fair Value	24,038
Government sponsored enterprise obligations
Schedule of Available-for-sale Securities [Line Items]
Available for sale, Less Than Twelve Months Gross Unrealized Losses	(1)
Available for sale, Less Than Twelve Months Fair Value	2,499
Mutual funds
Schedule of Available-for-sale Securities [Line Items]
Available for sale, Over Twelve Months Gross Unrealized Losses	(60)	(58)
Available for sale, Over twelve Months Fair Value	1,660	1,626
Common and preferred stock
Schedule of Available-for-sale Securities [Line Items]
Available for sale, Over Twelve Months Gross Unrealized Losses		(11)
Available for sale, Over twelve Months Fair Value		28
Private-label residential mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Available for sale, Over Twelve Months Gross Unrealized Losses		(501)
Available for sale, Over twelve Months Fair Value		$ 1,567