Summary of Significant Accounting Policies (Additional Cash Flow Information) (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Accounting Policies [Abstract]
Cash paid for interest	$ 22,449	$ 29,378	$ 46,801
Cash paid for income tax	49,514	58,950	54,437
Transfer of securities from available for sale to held to maturity	0	2,266,195	0
Unsettled purchases of securities	16,241	90,073	0
Loans foreclosed and transferred to other real estate owned and foreclosed assets	6,870	7,817	21,126
Loans to facilitate the sale of other real estate owned	678	0	75
Deferred gain on sale of building and parking garage	768	0	0
Common stock/treasury stock issued to the Corporation's 401(k) plan	$ 0	$ 0	$ 1,360