Credit Quality And Allowance For Credit Losses (Changes In The Allowance For Loan Losses And Related Loan Amounts) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Financing Receivable, Allowance for Credit Loss [Line Items]
Balance at beginning of period	$ 661	$ 618	$ 992
Provision for loan losses	89	60	(384)
Balance at end of period	$ 728	$ 661	$ 618
As a percentage of total loans	1.40%	1.24%	1.26%
Total allowance for loan losses	$ 728	$ 661	$ 618
Financing Receivable [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Balance at beginning of period	610	588	948
Loan charge-offs	(62)	(68)	(70)
Recoveries on loans previously charged-off	40	51	80
Net loan (charge-offs) recoveries	(22)	(17)	10
Provision for loan losses	100	39	(370)
Balance at end of period	$ 688	$ 610	$ 588
As a percentage of total loans	1.32%	1.14%	1.19%
Total allowance for loan losses	$ 688	$ 610	$ 588
Unused Commitments to Extend Credit
Financing Receivable, Allowance for Credit Loss [Line Items]
Balance at beginning of period	51	30	44
Provision for loan losses	(11)	21	(14)
Balance at end of period	40	51	30
Total allowance for loan losses	40	51	30
Business loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Balance at beginning of period	581	555	930
Provision for loan losses	91	44	(384)
Balance at end of period	$ 651	$ 581	$ 555
As a percentage of total loans	1.36%	1.18%	1.22%
Total allowance for loan losses	$ 651	$ 581	$ 555
Business loans | Financing Receivable [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Balance at beginning of period	541	531	895
Loan charge-offs	(59)	(65)	(67)
Recoveries on loans previously charged-off	38	47	76
Net loan (charge-offs) recoveries	(21)	(18)	9
Provision for loan losses	100	28	(373)
Balance at end of period	$ 620	$ 541	$ 531
As a percentage of total loans	1.29%	1.10%	1.17%
Total allowance for loan losses	$ 620	$ 541	$ 531
Business loans | Unused Commitments to Extend Credit
Financing Receivable, Allowance for Credit Loss [Line Items]
Balance at beginning of period	40	24	35
Provision for loan losses	(9)	16	(11)
Balance at end of period	31	40	24
Total allowance for loan losses	31	40	24
Retail loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Balance at beginning of period	80	63	62
Provision for loan losses	(2)	16	0
Balance at end of period	$ 77	$ 80	$ 63
As a percentage of total loans	1.85%	1.96%	1.63%
Total allowance for loan losses	$ 77	$ 80	$ 63
Retail loans | Financing Receivable [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Balance at beginning of period	69	57	53
Loan charge-offs	(3)	(3)	(3)
Recoveries on loans previously charged-off	2	4	4
Net loan (charge-offs) recoveries	(1)	1	1
Provision for loan losses	0	11	3
Balance at end of period	$ 68	$ 69	$ 57
As a percentage of total loans	1.63%	1.67%	1.47%
Total allowance for loan losses	$ 68	$ 69	$ 57
Retail loans | Unused Commitments to Extend Credit
Financing Receivable, Allowance for Credit Loss [Line Items]
Balance at beginning of period	11	6	9
Provision for loan losses	(2)	5	(3)
Balance at end of period	9	11	6
Total allowance for loan losses	$ 9	$ 11	$ 6