Derivative Instruments (Gain (Loss) Recognized On Derivative Instruments Not Designated In Hedging Relationship) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Derivative [Line Items]
Total capital markets group derivatives	$ 6,033	$ 3,871	$ 13,382	$ 8,360
Total other derivatives	70	283	(35)	214
Total derivatives	6,103	4,154	13,347	8,574
Interest Rate Contract [Member]
Derivative [Line Items]
Total capital markets group derivatives	4,356	2,339	9,878	5,795
Foreign Exchange [Member]
Derivative [Line Items]
Total capital markets group derivatives	1,510	1,535	3,202	2,535
Total other derivatives	11	224	(171)	86
Credit Risk Contract [Member]
Derivative [Line Items]
Total capital markets group derivatives	167	(3)	302	30
Mortgage Banking Derivatives [Member]
Derivative [Line Items]
Total other derivatives	40	59	117	128
Warrants [Member]
Derivative [Line Items]
Total other derivatives	$ 19		$ 19