Goodwill And Other Intangible Assets (Narrative) (Detail) (USD $)	3 Months Ended		9 Months Ended		12 Months Ended	9 Months Ended			3 Months Ended	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2009 Customer Lists [Member]	Sep. 30, 2012 Core Deposits [Member]	Sep. 30, 2012 Community Banking [Member]	Sep. 30, 2012 Wealth Management [Member]	Mar. 31, 2012 Wealth Management [Member] Customer Lists [Member]	Sep. 30, 2012 Specialty Finance [Member]
Indefinite-lived Intangible Assets [Line Items]
Goodwill, Period Increase (Decrease)							$ 1,500,000	$ 1,800,000		$ 22,800,000
Amortization period in years, core deposit intangibles					18 years	10 years			10 years
Amortization of other intangible assets	$ 1,078,000	$ 970,000	$ 3,216,000	$ 2,363,000