v2.4.0.6
Fair Value of Available for Sale Securities and Related Gains and Losses Recognized in Accumulated Other Comprehensive Income or Loss (Detail) (USD $)
In Thousands, unless otherwise specified
Jun. 30, 2012
Dec. 31, 2011
Schedule of Available-for-sale Securities [Line Items]  
Amortized Cost$ 315,661$ 317,493
Gross Unrealized Gains5,7885,095
Gross Unrealized Losses(127)(76)
Fair Value321,322322,512
US Treasury and Government
  
Schedule of Available-for-sale Securities [Line Items]  
Amortized Cost135,012168,104
Gross Unrealized Gains1,1631,368
Gross Unrealized Losses(20)(12)
Fair Value136,155169,460
Residential Mortgage Backed Securities
  
Schedule of Available-for-sale Securities [Line Items]  
Amortized Cost179,589148,329
Gross Unrealized Gains4,6253,727
Gross Unrealized Losses(107)(64)
Fair Value184,107151,992
Corporate Securities
  
Schedule of Available-for-sale Securities [Line Items]  
Amortized Cost1,0601,060
Gross Unrealized Gains00
Gross Unrealized Losses00
Fair Value$ 1,060$ 1,060