Other services fees by major categories (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Component of Operating Other Cost and Expense [Line Items]
Debit card fees	$ 8,772	$ 13,075	$ 27,348	$ 39,795
Insurance Commissions And Fees	12,322	13,785	36,775	37,919
Fees And Commissions Credit Cards	14,576	13,738	41,403	36,106
Asset Management Fees	9,511	9,915	28,045	24,702
Servicing Fees Net	9,857	2,120	29,123	10,649
Fees And Commissions Fiduciary And Trust Activities	3,977	4,006	12,127	11,611
Processing fees	1,406	1,684	4,819	5,121
Other fees	4,363	4,341	13,210	13,720
Total other services fees	$ 64,784	$ 62,664	$ 192,850	$ 179,623