Intangible Assets (Schedule Of Acquired Intangible Assets) (Details) (USD $)
In Thousands, unless otherwise specified
Jun. 30, 2012
Dec. 31, 2011
Acquired Finite-Lived Intangible Assets [Line Items]    
Gross Carrying Amount $ 14,705 $ 14,705
Accumulated Amortization 9,916 9,441
Core Deposit Intangibles [Member]
   
Acquired Finite-Lived Intangible Assets [Line Items]    
Gross Carrying Amount 14,124 14,124
Accumulated Amortization 9,916 9,441
Missouri Charter [Member]
   
Acquired Finite-Lived Intangible Assets [Line Items]    
Gross Carrying Amount 581 581
Accumulated Amortization