Stockholders' Equity - Changes in Common Shares and Treasury Stock (Details) - USD ($)	Mar. 31, 2022	Dec. 31, 2021	Dec. 31, 2019
Class of Stock [Line Items]
Common stock, shares authorized	6,000,000,000
Preferred stock, shares authorized	1,000,000,000
Stock repurchase program, remaining authorized repurchase amount	$ 319,000,000
December 2018 Share Repurchase Program
Class of Stock [Line Items]
Stock repurchase program, authorized amount			$ 2,000,000,000
December 2021 Share Repurchase Program
Class of Stock [Line Items]
Stock repurchase program, authorized amount		$ 3,500,000,000