Leases (Narrative) (Details) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2021 USD ($) branch	Jun. 30, 2020 USD ($)	Jun. 30, 2021 USD ($) branch	Jun. 30, 2020 USD ($)	Dec. 31, 2020 USD ($)
Leases [Abstract]
Number of branches \| branch	419		419
Number of branches owned \| branch	273		273
Number of branches leased \| branch	146		146
Operating right-of-use assets, net of amortization	$ 202		$ 202		$ 213
Finance lease assets	4		4		4
Operating lease income	3	$ 3	7	$ 6
Sales-type or direct financing leases	307		307		$ 320
Sales-type or direct financing leases income	$ 3	$ 3	$ 6	$ 7

Amount, after accumulated amortization, of right-of-use asset from finance lease.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 45
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123391704&loc=SL77918627-209977

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- Definition

Amount of operating lease income from lease payments and variable lease payments paid and payable to lessor. Includes, but is not limited to, variable lease payments not included in measurement of lease receivable.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 30
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=124258985&loc=SL77919372-209981

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-Name Accounting Standards Codification
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
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Amount of lessee's right to use underlying asset under operating lease.

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Present value of lease payments not yet received by lessor and amount expected to be derived from underlying asset, following end of lease term guaranteed by lessee or other third party unrelated to lessor, from sales-type and direct financing leases.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 30
-Section 50
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=124258985&loc=SL77919391-209981

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Amount of profit (loss) for sales-type lease and (loss) for direct financing lease recognized at commencement.

+ References

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Number of Branches

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Number of Branches Leased

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Number of Branches Owned

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