Investment Securities (Schedule Of OTTI For Single Issuer Trust Preferred Securities) (Detail) (USD $) In Thousands, unless otherwise specified					12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012 Single Issuer Trust Preferred Securities [Member]	Dec. 31, 2011 Single Issuer Trust Preferred Securities [Member]	Dec. 31, 2012 Single Issuer Trust Preferred Securities [Member] Security B [Member]		Dec. 31, 2012 Single Issuer Trust Preferred Securities [Member] Security C [Member]		Dec. 31, 2012 Single Issuer Trust Preferred Securities [Member] Security D [Member]		Dec. 31, 2012 Single Issuer Trust Preferred Securities [Member] Security E [Member]		Dec. 31, 2012 Single Issuer Trust Preferred Securities [Member] Security F [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Amortized Cost	$ 3,069,182	$ 2,849,463	$ 51,181	$ 51,027	$ 6,893		$ 8,673		$ 9,542		$ 11,766		$ 14,307
Gross Unrealized Losses	(31,489)	(51,186)	(6,766)	(12,813)	(1,174)		(974)		(1,090)		(1,379)		(2,149)
Fair Value			$ 44,415		$ 5,719		$ 7,699		$ 8,452		$ 10,387		$ 12,158
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.