Loans And Allowance For Credit Losses (Summary Of Changes In The Allowance For Credit Losses) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014	Dec. 31, 2013
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan and Lease Losses, Provision for Loss, Gross	$ 1,494	$ 610
Change In Allowance Covered By F D I C Indemnification	(38)	(817)
Allowance for Loan and Lease Losses, Write-offs	(20,188)	(20,795)
Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	604,663	746,291
Net loan and lease charge-offs	16,882	(7,911)
Balance at end of period	82,287	88,693	81,076	89,705
Allowance for loan losses	620,013	736,953
Reserve for unfunded lending commitments	82,287	88,693	81,076	89,705
Total allowance for credit losses	702,300	825,646
Allowance for Loan and Lease Losses, Recoveries of Bad Debts	37,070	12,884
Provision for Unfunded Lending Commitments	1,211	1,012
Balance at end of period	620,013	736,953
Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan and Lease Losses, Provision for Loss, Gross	(24,934)	(11,260)
Change In Allowance Covered By F D I C Indemnification	(38)	(781)
Allowance for Loan and Lease Losses, Write-offs	(15,951)	(9,796)
Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	412,514	469,213
Net loan and lease charge-offs	4,662	(1,991)
Balance at end of period	62,775	49,870	58,931	48,345
Allowance for loan losses	442,072	477,701
Reserve for unfunded lending commitments	62,775	49,870	58,931	48,345
Total allowance for credit losses	504,847	527,571
Allowance for Loan and Lease Losses, Recoveries of Bad Debts	20,613	7,805
Provision for Unfunded Lending Commitments	3,844	1,525
Balance at end of period	442,072	477,701
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan and Lease Losses, Provision for Loss, Gross	(26,887)	2,891
Change In Allowance Covered By F D I C Indemnification		0
Allowance for Loan and Lease Losses, Write-offs	(626)	(7,854)
Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	145,009	216,012
Net loan and lease charge-offs	13,493	(4,972)
Balance at end of period	18,937	35,273	21,517	37,485
Allowance for loan losses	131,615	208,149
Reserve for unfunded lending commitments	18,937	35,273	21,517	37,485
Total allowance for credit losses	150,552	243,422
Allowance for Loan and Lease Losses, Recoveries of Bad Debts	14,119	2,882
Provision for Unfunded Lending Commitments	2,580	2,212
Balance at end of period	131,615	208,149
Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan and Lease Losses, Provision for Loss, Gross	(459)	8,979
Change In Allowance Covered By F D I C Indemnification		(36)
Allowance for Loan and Lease Losses, Write-offs	(3,611)	(3,145)
Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	47,140	61,066
Net loan and lease charge-offs	(1,273)	(948)
Balance at end of period	575	3,550	628	3,875
Allowance for loan losses	46,326	51,103
Reserve for unfunded lending commitments	575	3,550	628	3,875
Total allowance for credit losses	46,901	54,653
Allowance for Loan and Lease Losses, Recoveries of Bad Debts	2,338	2,197
Provision for Unfunded Lending Commitments	53	(325)
Balance at end of period	$ 46,326	$ 51,103