Condensed Consolidated Balance Sheet (unaudited) (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2024	Dec. 31, 2023
Statement of Financial Position [Abstract]
Available-for-sale securities, amortized cost	$ 27,705	$ 28,416
Held-to-maturity securities, fair value	$ 4,503	$ 4,729
Common stock, par value per share (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	1,100,000,000	1,100,000,000
Common stock, shares issued (in shares)	514,851,483	511,861,447
Common stock, shares outstanding (in shares)	304,655,610	302,459,258
Treasury stock, common, shares (in shares)	210,195,873	209,402,189