Business Segment Information (Amounts Of Consolidated Revenue, Expense, Tax And Assets) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Segment Reporting Information [Line Items]
Net interest income	$ 176,264	$ 166,640	$ 348,338	$ 323,506
Provision/(provision credit) for loan losses	4,000	2,000	7,000	7,000
Noninterest income	145,514	130,301	279,819	259,990
Noninterest expense	226,822	218,394	453,749	594,615
Income/(loss) before income taxes	90,956	76,547	167,408	(18,119)
Provision/(benefit) for income taxes	30,016	21,590	54,255	(671)
Net income/(loss)	60,940	54,957	113,153	(17,448)
Average assets	26,828,548	25,411,578	26,723,621	25,526,120
Regional Banking [Member]
Segment Reporting Information [Line Items]
Net interest income	178,321	165,903	350,634	320,311
Provision/(provision credit) for loan losses	10,883	17,078	25,650	21,993
Noninterest income	61,275	65,983	120,551	126,179
Noninterest expense	164,315	143,960	309,666	279,437
Income/(loss) before income taxes	64,398	70,848	135,869	145,060
Provision/(benefit) for income taxes	22,455	25,086	47,881	51,582
Net income/(loss)	41,943	45,762	87,988	93,478
Average assets	16,575,676	15,021,991	16,260,430	14,626,026
Fixed Income [Member]
Segment Reporting Information [Line Items]
Net interest income	3,147	4,293	5,813	8,613
Noninterest income	78,083	56,002	145,205	117,566
Noninterest expense	62,881	51,253	121,549	105,992
Income/(loss) before income taxes	18,349	9,042	29,469	20,187
Provision/(benefit) for income taxes	6,755	3,154	10,630	7,298
Net income/(loss)	11,594	5,888	18,839	12,889
Average assets	2,470,699	2,417,317	2,370,179	2,432,194
Corporate [Member]
Segment Reporting Information [Line Items]
Net interest income	(15,850)	(17,366)	(30,214)	(33,440)
Noninterest income	4,909	3,901	10,632	9,286
Noninterest expense	16,072	14,061	29,551	28,403
Income/(loss) before income taxes	(27,013)	(27,526)	(49,133)	(52,557)
Provision/(benefit) for income taxes	(12,840)	(15,991)	(24,094)	(27,694)
Net income/(loss)	(14,173)	(11,535)	(25,039)	(24,863)
Average assets	5,833,122	5,562,880	6,097,578	5,985,074
Non Strategic [Member]
Segment Reporting Information [Line Items]
Net interest income	10,646	13,810	22,105	28,022
Provision/(provision credit) for loan losses	(6,883)	(15,078)	(18,650)	(14,993)
Noninterest income	1,247	4,415	3,431	6,959
Noninterest expense	(16,446)	9,120	(7,017)	180,783
Income/(loss) before income taxes	35,222	24,183	51,203	(130,809)
Provision/(benefit) for income taxes	13,646	9,341	19,838	(31,857)
Net income/(loss)	21,576	14,842	31,365	(98,952)
Average assets	$ 1,949,051	$ 2,409,390	$ 1,995,434	$ 2,482,826