Condensed Consolidated Balance Sheet (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
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)	506,435,119	504,521,535
Common stock, shares outstanding (in shares)	327,306,298	337,940,636
Treasury stock, shares (in shares)	179,128,821	166,580,899
Available-for-sale debt securities \| Available-for-sale securities
Available-for-sale securities, amortized cost	$ 35,592	$ 33,650
Held-to-maturity securities
Held-to-maturity securities, fair value	1,106	1,204
Held-to-maturity securities \| Held-to-maturity securities
Held-to-maturity securities, fair value	$ 1,106	$ 1,204

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