Goodwill and Other Intangible Assets - Gross Carrying Amount and Accumulated Amortization of Intangible Assets (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Goodwill [Line Items]
Gross Carrying Amount	$ 526	$ 452
Accumulated Amortization	499	397
Core deposit intangibles
Goodwill [Line Items]
Gross Carrying Amount	356	356
Accumulated Amortization	342	326
PCCR intangibles
Goodwill [Line Items]
Gross Carrying Amount	16	16
Accumulated Amortization	16	15
Other intangible assets
Goodwill [Line Items]
Gross Carrying Amount	154	80
Accumulated Amortization	$ 141	$ 56