Securities (Detail) - Changes In Credit Losses Recognized In Earnings (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Cumulative amount recognized at the beginning of the year	$ 38,803		$ 36,525		$ 35,589
OTTI included in earnings
Losses on securities that previously had OTTI	0	[1]	2,278	[1]	936	[1]
Losses on securities that did not previously have OTTI	408	[1]	1,391	[1]	0	[1]
Reduction for securities sold during the year	(6,789)	[2]	(1,391)	[2]	0	[2]
Cumulative amount recognized at the end of the year	$ 32,422		$ 38,803		$ 36,525

[1] Included in net securities gains (losses) in the Consolidated Statements of Income.

[2] During the year ended December 31, 2013, one CDO with a carrying value of zero was sold, resulting in a gain of $101,000. This CDO had OTTI of $6.8 million that was previously recognized in earnings.