Investment Securities (Schedule Of OTTI For Single Issuer Trust Preferred Securities) (Detail) (USD $) In Thousands, unless otherwise specified				9 Months Ended
	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013 Single issuer trust preferred securities [Member]	Sep. 30, 2013 Single issuer trust preferred securities [Member] Security B [Member]		Sep. 30, 2013 Single issuer trust preferred securities [Member] Security C [Member]		Sep. 30, 2013 Single issuer trust preferred securities [Member] Security D [Member]		Sep. 30, 2013 Single issuer trust preferred securities [Member] Security E [Member]		Sep. 30, 2013 Single issuer trust preferred securities [Member] Security F [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Amortized Cost	$ 3,181,393	$ 3,069,182	$ 51,311	$ 6,922		$ 8,705		$ 9,547		$ 11,804		$ 14,333
Gross Unrealized Losses	(52,549)	(31,489)	(8,009)	(922)		(1,280)		(1,847)		(1,387)		(2,573)
Fair Value	$ 3,193,772	$ 3,136,160	$ 43,302	$ 6,000		$ 7,425		$ 7,700		$ 10,417		$ 11,760
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.