Goodwill And Other Intangible Assets (Other Intangible Assets) (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Goodwill And Other Intangible Assets [Line Items]
Gross Carrying Amount - Other Intangible Assets	$ 23,130	$ 22,993
Accumulated Amortization - Other Intangible Assets	8,978	7,640
Net Carrying Amount - Other Intangible Assets	14,152	15,353
Core Deposits [Member]
Goodwill And Other Intangible Assets [Line Items]
Gross Carrying Amount - Other Intangible Assets	18,093	18,093
Accumulated Amortization - Other Intangible Assets	6,222	5,079
Net Carrying Amount - Other Intangible Assets	11,871	13,014
Customer Relationships [Member]
Goodwill And Other Intangible Assets [Line Items]
Gross Carrying Amount - Other Intangible Assets	5,037	4,900
Accumulated Amortization - Other Intangible Assets	2,756	2,561
Net Carrying Amount - Other Intangible Assets	$ 2,281	$ 2,339