Loans And Allowance For Credit Losses (Summary Of Information On Impaired Loans) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	$ 602,656	$ 532,395
Impaired Financing Receivable, Recorded Investment	659,759	566,599
Impaired Financing Receivable, Related Allowance	63,223	48,697
Impaired Financing Receivable, Interest Income, Accrual Method	32,510	48,563
Impaired Financing Receivable, Unpaid Principal Balance	771,394	687,148
Commercial And Industrial [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	332,775	153,756
Impaired Financing Receivable, Recorded Investment	392,937	207,919
Impaired Financing Receivable, Related Allowance	52,164	30,538
Impaired Financing Receivable, Interest Income, Accrual Method	4,783	7,506
Impaired Financing Receivable, Unpaid Principal Balance	469,880	272,161
Owner Occupied [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	98,903	125,777
Impaired Financing Receivable, Recorded Investment	100,696	126,267
Impaired Financing Receivable, Related Allowance	3,138	5,486
Impaired Financing Receivable, Interest Income, Accrual Method	9,082	12,450
Impaired Financing Receivable, Unpaid Principal Balance	110,779	141,526
Municipal [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	892	994
Impaired Financing Receivable, Recorded Investment	852	951
Impaired Financing Receivable, Related Allowance	0	0
Impaired Financing Receivable, Interest Income, Accrual Method	0	0
Impaired Financing Receivable, Unpaid Principal Balance	1,331	1,430
Commercial Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	432,570	280,527
Impaired Financing Receivable, Recorded Investment	494,485	335,137
Impaired Financing Receivable, Related Allowance	55,302	36,024
Impaired Financing Receivable, Interest Income, Accrual Method	13,865	19,956
Impaired Financing Receivable, Unpaid Principal Balance	581,990	415,117
Term [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	76,421	111,074
Impaired Financing Receivable, Recorded Investment	69,712	117,225
Impaired Financing Receivable, Related Allowance	1,305	2,604
Impaired Financing Receivable, Interest Income, Accrual Method	12,810	16,971
Impaired Financing Receivable, Unpaid Principal Balance	78,991	142,239
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	87,327	127,266
Impaired Financing Receivable, Recorded Investment	83,419	131,859
Impaired Financing Receivable, Related Allowance	1,529	3,222
Impaired Financing Receivable, Interest Income, Accrual Method	15,135	23,381
Impaired Financing Receivable, Unpaid Principal Balance	100,882	165,030
Home Equity Credit Line [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	21,680	22,050
Impaired Financing Receivable, Recorded Investment	22,297	24,299
Impaired Financing Receivable, Related Allowance	477	243
Impaired Financing Receivable, Interest Income, Accrual Method	1,324	1,547
Impaired Financing Receivable, Unpaid Principal Balance	24,531	27,064
One Through Four Family Residential [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	56,573	96,482
Impaired Financing Receivable, Recorded Investment	55,796	70,695
Impaired Financing Receivable, Related Allowance	5,549	8,736
Impaired Financing Receivable, Interest Income, Accrual Method	1,683	2,616
Impaired Financing Receivable, Unpaid Principal Balance	59,271	74,009
Construction And Other Consumer Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	2,487	2,288
Impaired Financing Receivable, Recorded Investment	2,622	2,003
Impaired Financing Receivable, Related Allowance	364	173
Impaired Financing Receivable, Interest Income, Accrual Method	132	123
Impaired Financing Receivable, Unpaid Principal Balance	3,128	2,741
Bankcard And Other Revolving Plans [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	0	1
Impaired Financing Receivable, Recorded Investment	0	0
Impaired Financing Receivable, Related Allowance	0	0
Impaired Financing Receivable, Interest Income, Accrual Method	18	102
Impaired Financing Receivable, Unpaid Principal Balance	0	0
Consumer Other Financing Receivable [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	2,019	3,781
Impaired Financing Receivable, Recorded Investment	1,140	2,606
Impaired Financing Receivable, Related Allowance	2	299
Impaired Financing Receivable, Interest Income, Accrual Method	353	838
Impaired Financing Receivable, Unpaid Principal Balance	1,592	3,187
Commercial Real Estate Construction [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	10,906	16,192
Impaired Financing Receivable, Recorded Investment	13,707	14,634
Impaired Financing Receivable, Related Allowance	224	618
Impaired Financing Receivable, Interest Income, Accrual Method	2,325	6,410
Impaired Financing Receivable, Unpaid Principal Balance	21,891	22,791
Consumer Loan [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	82,759	124,602
Impaired Financing Receivable, Recorded Investment	81,855	99,603
Impaired Financing Receivable, Related Allowance	6,392	9,451
Impaired Financing Receivable, Interest Income, Accrual Method	3,510	5,226
Impaired Financing Receivable, Unpaid Principal Balance	88,522	107,001
Impaired Financing Receivable Recorded Investment With an Allowance [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	400,846	300,949
Impaired Financing Receivable Recorded Investment With an Allowance [Member] | Commercial And Industrial [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	310,740	163,729
Impaired Financing Receivable Recorded Investment With an Allowance [Member] | Owner Occupied [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	29,713	43,243
Impaired Financing Receivable Recorded Investment With an Allowance [Member] | Municipal [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	0	0
Impaired Financing Receivable Recorded Investment With an Allowance [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	340,453	206,972
Impaired Financing Receivable Recorded Investment With an Allowance [Member] | Term [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	16,725	34,361
Impaired Financing Receivable Recorded Investment With an Allowance [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	23,339	43,919
Impaired Financing Receivable Recorded Investment With an Allowance [Member] | Home Equity Credit Line [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	6,831	5,319
Impaired Financing Receivable Recorded Investment With an Allowance [Member] | One Through Four Family Residential [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	28,430	41,155
Impaired Financing Receivable Recorded Investment With an Allowance [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	1,763	1,014
Impaired Financing Receivable Recorded Investment With an Allowance [Member] | Bankcard And Other Revolving Plans [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	0	0
Impaired Financing Receivable Recorded Investment With an Allowance [Member] | Consumer Other Financing Receivable [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	30	2,570
Impaired Financing Receivable Recorded Investment With an Allowance [Member] | Commercial Real Estate Construction [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	6,614	9,558
Impaired Financing Receivable Recorded Investment With an Allowance [Member] | Consumer Loan [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	37,054	50,058
Impaired Financing Receivable Recorded Investment With No Allowance [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	258,913	265,650
Impaired Financing Receivable Recorded Investment With No Allowance [Member] | Commercial And Industrial [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	82,197	44,190
Impaired Financing Receivable Recorded Investment With No Allowance [Member] | Owner Occupied [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	70,983	83,024
Impaired Financing Receivable Recorded Investment With No Allowance [Member] | Municipal [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	852	951
Impaired Financing Receivable Recorded Investment With No Allowance [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	154,032	128,165
Impaired Financing Receivable Recorded Investment With No Allowance [Member] | Term [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	52,987	82,864
Impaired Financing Receivable Recorded Investment With No Allowance [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	60,080	87,940
Impaired Financing Receivable Recorded Investment With No Allowance [Member] | Home Equity Credit Line [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	15,466	18,980
Impaired Financing Receivable Recorded Investment With No Allowance [Member] | One Through Four Family Residential [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	27,366	29,540
Impaired Financing Receivable Recorded Investment With No Allowance [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	859	989
Impaired Financing Receivable Recorded Investment With No Allowance [Member] | Bankcard And Other Revolving Plans [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	0	0
Impaired Financing Receivable Recorded Investment With No Allowance [Member] | Consumer Other Financing Receivable [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	1,110	36
Impaired Financing Receivable Recorded Investment With No Allowance [Member] | Commercial Real Estate Construction [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	7,093	5,076
Impaired Financing Receivable Recorded Investment With No Allowance [Member] | Consumer Loan [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	$ 44,801	$ 49,545