Investment Securities (Schedule Of Trust Preferred Securities - Pooled Issuers For OTTI Information) (Detail) (USD $) In Thousands, unless otherwise specified					9 Months Ended
	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013 Pooled trust preferred securities [Member]		Sep. 30, 2013 Pooled trust preferred securities [Member] Preferred Class B [Member] Security H [Member]		Sep. 30, 2013 Pooled trust preferred securities [Member] Preferred Class B [Member] Security I [Member]		Sep. 30, 2013 Pooled trust preferred securities [Member] Preferred Class B [Member] Security J [Member]		Sep. 30, 2013 Pooled trust preferred securities [Member] Preferred Class B [Member] Security L [Member]		Sep. 30, 2013 Pooled trust preferred securities [Member] Preferred Class A [Member] Security K [Member]		Sep. 30, 2013 Pooled trust preferred securities [Member] Preferred Class A [Member] Security M [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Amortized Cost	$ 3,181,393	$ 3,069,182	$ 36,581	[1]	$ 3,487	[1]	$ 4,468	[1]	$ 5,321	[1]	$ 8,728	[1]	$ 7,432	[1]	$ 7,145	[1]
Gross Unrealized Losses	(52,549)	(31,489)	(6,617)		(533)		(716)		(1,067)		(1,449)		(1,107)		(1,745)
Fair Value	3,193,772	3,136,160	29,964		2,954		3,752		4,254		7,279		6,325		5,400
Lowest Credit Ratings					B	[2]	CCC	[2]	CCC	[2]	CCC	[2]	CCC	[2]	D	[2]
Total OTTI			$ (9,356)		$ (352)		$ (365)		$ (806)		$ (867)		$ (2,040)		$ (4,926)
% of Performing Bank/ Insurance Issuers					91.70%		87.50%		91.70%		91.30%		69.10%		60.70%
Deferrals/ Defaults (As a % of Current Collateral)					8.00%		17.20%		10.40%		13.20%		33.50%		34.60%

[1] For the securities previously deemed impaired, the amortized cost is reflective of previous OTTI recognized in earnings.

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