Goodwill and Other Intangible Assets (Goodwill And Other Intangible Assets, Net Of Accumulated Amortization) (Detail) - USD ($) $ in Thousands		12 Months Ended
	Jan. 13, 2015	Dec. 31, 2015
Goodwill [Roll Forward]
Goodwill, beginning balance		$ 529,887
Goodwill acquired	$ 8,486	8,486
Goodwill, ending balance		538,373
Community Banking [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance		516,560
Goodwill acquired		0
Goodwill, ending balance		516,560
HSA Bank [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance		13,327
Goodwill acquired		8,486
Goodwill, ending balance		$ 21,813