Commitments and Contingencies - Tax Credits and Amortization (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021		Dec. 31, 2020		Dec. 31, 2019
Investments in affordable housing projects
Income Tax Contingency [Line Items]
Investment tax credit	$ 477		$ 454		$ 284
Amortization and other changes in carrying amount	472		455		279
Other Community Development Investment
Income Tax Contingency [Line Items]
Investment tax credit	103		96		39
Amortization and other changes in carrying amount	86		81		28
Renewable energy investments
Income Tax Contingency [Line Items]
Investment tax credit	157	[1]	159	[1]	0
Amortization and other changes in carrying amount	$ 4		$ 4		$ 4

[1] Tax credits received for these investments are recorded as a reduction to the carrying value of these investments