Composition of Loans, Net of Unearned income (Parenthetical) (Detail) (USD $)	Dec. 31, 2012		Dec. 31, 2011
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	$ 8,946,933,000	[1]	$ 6,970,082,000	[1]
Credit Card Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross	64,000,000		50,000,000
Consumer Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	829,957,000		695,138,000
Real estate secured loans | Consumer Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	685,300,000	[2]	534,001,000	[2]
Real estate secured loans | Consumer Portfolio Segment [Member] | Loans for personal residence
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	503,378,000		350,359,000
Real estate secured loans | Consumer Portfolio Segment [Member] | Loans to eligible employees
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	110,584,000		99,704,000
Real estate secured loans | Consumer Portfolio Segment [Member] | Home equity lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	71,338,000		83,938,000
Premium wine | Consumer Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans Receivable, Gross, Commercial, Construction	$ 148,000,000		$ 111,000,000

[1] Included within our total loan portfolio are credit card loans of $64 million and $50 million at December 31, 2012 and 2011, respectively.

[2] Consumer loans secured by real estate at December 31, 2012 and 2011 were comprised of the following: