Stockholders' Equity - Common Stock Repurchased (Details) - USD ($) $ / shares in Units, $ in Billions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Class of Stock [Line Items]
Common stock repurchased under repurchase programs (in shares)	9,533,392	48,702,830
Average purchase price per share (in usd per share)	$ 18.46	$ 15.75
Shares repurchased related to employee stock-based compensation plans (in shares)	934,602	1,059,980
Average purchase price per share (in usd per share)	$ 18.55	$ 13.50
Common shares issued (in shares)	2,594,817	2,826,387
Remaining authority under the share repurchase program	$ 1.1
Common stock repurchased and cancelled (in shares)		28,500,000
2021 Share Repurchase Program, Accelerated Purchases
Class of Stock [Line Items]
Common stock repurchased under repurchase programs (in shares)		13,000,000