Loans And Allowance For Credit Losses (Summary Of Changes In The Allowance For Credit Losses) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Jun. 30, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Dec. 31, 2013
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan and Lease Losses, Provision for Loss, Gross	$ (18,262)	$ 54,643	$ (17,334)	$ 109,669
Change In Allowance Covered By F D I C Indemnification	0	(25)	0	(1,286)
Allowance for Loan and Lease Losses, Write-offs	(42,359)	(26,471)	(93,595)	(70,666)
Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	609,375	675,907	604,663	746,291
Net loan and lease charge-offs	(31,197)	(10,962)	(25,557)	(25,059)
Balance at end of period	81,389	79,377	81,389	79,377
Allowance for loan losses	609,375	675,907	604,663	746,291	$ 596,440	$ 609,375	$ 604,663	$ 610,277	$ 675,907	$ 746,291
Reserve for unfunded lending commitments	81,389	79,377	81,389	79,377	81,389	79,961	81,076	79,377	95,472	89,705
Total allowance for credit losses					677,829			689,654
Allowance for Loan and Lease Losses, Recoveries of Bad Debts	11,162	15,509	68,038	45,607
Provision for Unfunded Lending Commitments	1,428	(16,095)	313	(10,328)
Balance at end of period	596,440	610,277	596,440	610,277
Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan and Lease Losses, Provision for Loss, Gross	(22,417)	19,960	(53,292)	38,274
Change In Allowance Covered By F D I C Indemnification	0	(25)	(57)	(1,190)
Allowance for Loan and Lease Losses, Write-offs	(36,961)	(20,084)	(76,734)	(45,903)
Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	437,770	442,965	412,514	469,213
Net loan and lease charge-offs	(32,490)	(10,935)	(38,052)	(17,704)
Balance at end of period	63,582	54,452	63,582	54,452
Allowance for loan losses	437,770	442,965	412,514	469,213	427,697	437,770	412,514	412,045	442,965	469,213
Reserve for unfunded lending commitments	63,582	54,452	63,582	54,452	63,582	60,774	58,931	54,452	52,801	48,345
Total allowance for credit losses					491,279			466,497
Allowance for Loan and Lease Losses, Recoveries of Bad Debts	4,471	9,149	38,682	28,199
Provision for Unfunded Lending Commitments	2,808	1,651	4,651	6,107
Balance at end of period	427,697	412,045	427,697	412,045
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan and Lease Losses, Provision for Loss, Gross	6,621	34,187	38,491	57,350
Change In Allowance Covered By F D I C Indemnification	0	0	57	0
Allowance for Loan and Lease Losses, Write-offs	(1,068)	(3,320)	(5,637)	(14,135)
Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	125,796	187,940	145,009	216,012
Net loan and lease charge-offs	3,094	12	15,694	(4,897)
Balance at end of period	17,172	24,299	17,172	24,299
Allowance for loan losses	125,796	187,940	145,009	216,012	122,269	125,796	145,009	153,765	187,940	216,012
Reserve for unfunded lending commitments	17,172	24,299	17,172	24,299	17,172	18,639	21,517	24,299	38,689	37,485
Total allowance for credit losses					139,441			178,064
Allowance for Loan and Lease Losses, Recoveries of Bad Debts	4,162	3,332	21,331	9,238
Provision for Unfunded Lending Commitments	(1,467)	(14,390)	(4,345)	(13,186)
Balance at end of period	122,269	153,765	122,269	153,765
Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan and Lease Losses, Provision for Loss, Gross	(2,466)	496	(2,533)	14,045
Change In Allowance Covered By F D I C Indemnification	0	0	0	(96)
Allowance for Loan and Lease Losses, Write-offs	(4,330)	(3,067)	(11,224)	(10,628)
Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	45,809	45,002	47,140	61,066
Net loan and lease charge-offs	(1,801)	(39)	(3,199)	(2,458)
Balance at end of period	635	626	635	626
Allowance for loan losses	45,809	45,002	47,140	61,066	46,474	45,809	47,140	44,467	45,002	61,066
Reserve for unfunded lending commitments	635	626	635	626	635	$ 548	$ 628	626	$ 3,982	$ 3,875
Total allowance for credit losses					$ 47,109			$ 45,093
Allowance for Loan and Lease Losses, Recoveries of Bad Debts	2,529	3,028	8,025	8,170
Provision for Unfunded Lending Commitments	87	(3,356)	7	(3,249)
Balance at end of period	$ 46,474	$ 44,467	$ 46,474	$ 44,467