Goodwill And Other Intangible Assets (Additional Information - Other Intangible Assets) (Detail)	6 Months Ended
Jun. 30, 2012
Core Deposits [Member]
Goodwill And Other Intangible Assets [Line Items]
Weighted average remaining life at period end (in years)	5 years
Customer Relationships [Member]
Goodwill And Other Intangible Assets [Line Items]
Weighted average remaining life at period end (in years)	7 years

Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

No definition available.

Name:	us-gaap_FiniteLivedIntangibleAssetUsefulLife
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration