Goodwill and Other Intangible Assets - Rollforward of Goodwill (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013 Community Banking [Member]	Dec. 31, 2012 Community Banking [Member]	Dec. 31, 2013 Wealth Management [Member]	Dec. 31, 2012 Wealth Management [Member]	Dec. 31, 2011 Wealth Management [Member]	Dec. 31, 2013 Insurance [Member]	Dec. 31, 2012 Insurance [Member]	Dec. 31, 2011 Insurance [Member]	Dec. 31, 2013 Consumer Finance [Member]	Dec. 31, 2012 Consumer Finance [Member]	Dec. 31, 2011 Consumer Finance [Member]
Goodwill [Line Items]
Goodwill, Beginning Balance	$ 675,555	$ 568,462	$ 656,776	$ 549,683	$ 8,020	$ 8,020	$ 8,020	$ 8,950	$ 8,950	$ 8,950	$ 1,809	$ 1,809	$ 1,809
Goodwill additions	88,693	107,093	88,693	107,093
Goodwill, Ending Balance	$ 764,248	$ 675,555	$ 745,469	$ 656,776	$ 8,020	$ 8,020	$ 8,020	$ 8,950	$ 8,950	$ 8,950	$ 1,809	$ 1,809	$ 1,809