Income Taxes - Affordable Housing Tax Credits (Details) - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Tax credit and other tax benefits	$ 2.0	$ 1.8	$ 1.7
Amount of amortization reported in income tax expense	1.6	1.4	$ 1.3
Carrying value of investments, reported in other assets	14.6	12.1
Amount of commitments, reported in account payable and other liabilities	$ 6.8	$ 5.4