Other services fees by major categories (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Component of Operating Other Cost and Expense [Line Items]
Debit card fees	$ 9,832	$ 12,925
Insurance Commissions And Fees	12,390	11,926
Fees And Commissions Credit Cards	11,892	10,576
Asset Management Fees	8,889	7,130
Servicing Fees Net	12,931	6,260
Fees And Commissions Fiduciary And Trust Activities	4,081	3,495
Processing fees	1,774	1,697
Other fees	4,250	4,643
Total other services fees	$ 66,039	$ 58,652