Restrictions on Dividends and Capital Actions (Details) - USD ($) $ / shares in Units, $ in Billions	3 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash and Cash Equivalents [Abstract]
Dividends from consolidated nonbank subsidiaries		$ 3.0	$ 1.3
Common stock, per share (in dollars per share)	$ 0.30	$ 1.14	$ 1.08	$ 0.94