Goodwill and Other Intangible Assets (Schedule of Intangible Assets and Related Accumulated Amortization) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 197	$ 195
Accumulated amortization	(195)	(195)
Net carrying amount	2	0
Core deposit intangibles
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	167	167
Accumulated amortization	(167)	(167)
Net carrying amount	0	0
Customer relationships and other intangibles
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	30	28
Accumulated amortization	(28)	(28)
Net carrying amount	$ 2	$ 0