Investment Securities (Schedule Of OTTI For Single Issuer Trust Preferred Securities) (Detail) (USD $) In Thousands, unless otherwise specified					6 Months Ended
	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2013 Single Issuer Trust Preferred Securities [Member]	Dec. 31, 2012 Single Issuer Trust Preferred Securities [Member]	Jun. 30, 2013 Single Issuer Trust Preferred Securities [Member] Security B [Member]		Jun. 30, 2013 Single Issuer Trust Preferred Securities [Member] Security C [Member]		Jun. 30, 2013 Single Issuer Trust Preferred Securities [Member] Security D [Member]		Jun. 30, 2013 Single Issuer Trust Preferred Securities [Member] Security E [Member]		Jun. 30, 2013 Single Issuer Trust Preferred Securities [Member] Security F [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Amortized Cost	$ 3,253,001	$ 3,069,182	$ 51,267	$ 51,181	$ 6,912		$ 8,694		$ 9,546		$ 11,791		$ 14,324
Gross Unrealized Losses	(58,758)	(31,489)	(6,392)	(6,766)	(1,024)		(1,094)		(1,146)		(964)		(2,164)
Available for sale - Fair Value	$ 3,257,360	$ 3,136,160	$ 44,875	$ 44,415	$ 5,888		$ 7,600		$ 8,400		$ 10,827		$ 12,160
Lowest Credit Ratings					BB	[1]	BBB	[1]	B	[1]	BBB	[1]	BBB	[1]

[1] The Company utilized credit ratings provided by Moody’s, S&P and Fitch in its evaluation of issuers.