Goodwill and Other Intangible Assets (Goodwill And Other Intangible Assets) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Goodwill [Roll Forward]
Goodwill, Total, Beginning Balance	$ 764,305
Goodwill, Total, Ending Balance	1,786,225	764,305
Finite-lived Intangible Assets [Roll Forward]
Other Intangible Assets, Amortization	(10,207)	(4,781)	(4,816)
Other Intangible Assets, Net, Ending Balance	56,733
Community Banking [Member]
Goodwill [Roll Forward]
Goodwill, Gross, Beginning Balance	877,239	781,106	769,013
Goodwill, Impaired, Accumulated Impairment Loss, Beginning Balance	(112,934)	(112,934)	(112,934)
Goodwill, Total, Beginning Balance	764,305	668,172	656,079
Goodwill, Net additions	1,021,920	96,777	12,545
Goodwill, Reductions	0	(644)	(452)
Goodwill, Gross, Ending Balance	1,899,159	877,239	781,106
Goodwill, Impaired, Accumulated Impairment Loss, Ending Balance	(112,934)	(112,934)	(112,934)
Goodwill, Total, Ending Balance	1,786,225	764,305	668,172
Other Intagible Assets [Member]
Finite-lived Intangible Assets [Roll Forward]
Other Intangible Assets, Gross, Beginning Balance	58,909	58,909	58,079
Other Intangible Assets, Accumulated Amortization, Beginning Balance	(46,531)	(41,750)	(36,934)
Other Intangible Assets, Net, Beginning Balance	12,378	17,159	21,145
Other Intangible Assets, Net additions	54,562	0	830
Other Intangible Assets, Amortization	(10,207)	(4,781)	(4,816)
Other Intangible Assets, Gross, Ending Balance	113,471	58,909	58,909
Other Intangible Assets, Accumulated Amortization, Ending Balance	(56,738)	(46,531)	(41,750)
Other Intangible Assets, Net, Ending Balance	$ 56,733	$ 12,378	$ 17,159