Stockholders' Equity, Comprehensive Income and Share-Based Compensation - Additional Information (Details) $ / shares in Units, shares in Millions	1 Months Ended			3 Months Ended		9 Months Ended
	Jun. 30, 2021 $ / shares	Mar. 31, 2021 USD ($) $ / shares	Dec. 31, 2020 $ / shares	Aug. 01, 2021 USD ($) $ / shares shares	Jul. 26, 2020 $ / shares	Aug. 01, 2021 USD ($) employee_stock_purchase_plan $ / shares shares	Jul. 26, 2020 USD ($) $ / shares shares	Sep. 01, 2021 shares	Mar. 11, 2021 shares	Feb. 28, 2018 USD ($)
Equity [Line Items]
Tax effects on the unrealized loss on derivative instruments qualifying as cash flow hedges | $						$ 0	$ 32,000,000
Amount authorized by board of directors to repurchase shares | $		$ 7,500,000,000								$ 6,000,000,000
Remaining authorized repurchase amount | $				$ 6,500,000,000		$ 6,500,000,000
Dividends declared per share (in dollars per share) | $ / shares	$ 0.24	$ 0.24	$ 0.22	$ 0.24	$ 0.22	$ 0.70	$ 0.65
Payments of dividends | $						$ 622,000,000	$ 587,000,000
Employee Stock
Equity [Line Items]
Performance of total shareholder return						100.00%
Total unrecognized compensation expense | $				$ 547,000,000		$ 547,000,000
Weighted average period for unrecognized compensation expense to be recognized (in years)						2 years 8 months 12 days
Performance Shares
Equity [Line Items]
Additional performance-based awards to be earned upon certain levels of achievement (in shares)				1.3		1.3
Award measurement metric relative weight						50.00%
Award measurement period						3 years
Performance Shares | Executive Officers
Equity [Line Items]
Award measurement period						5 years
Performance Shares | Minimum
Equity [Line Items]
Award vesting rights, percentage of target amount						0.00%
Performance Shares | Minimum | Executive Officers
Equity [Line Items]
Award vesting rights, percentage of target amount						0.00%
Performance Shares | Maximum
Equity [Line Items]
Award vesting rights, percentage of target amount						200.00%
Performance Shares | Maximum | Executive Officers
Equity [Line Items]
Award vesting rights, percentage of target amount						200.00%
Employee Stock Incentive Plan
Equity [Line Items]
Increase in capital shares reserved for future issuance (in shares)									10.0
Number of shares available for grant (in shares)				35.0		35.0
Employee Stock Purchase Plan
Equity [Line Items]
Number of employee stock purchase plans | employee_stock_purchase_plan						2
Shares issued under employee stock purchase plans (in shares)						2.0	2.0
Number of shares available for grant (in shares)				8.0		8.0
Employee stock purchase plan purchase period						6 months
Employee Stock Purchase Plan | Forecast
Equity [Line Items]
Increase in capital shares reserved for future issuance (in shares)								11.3
Employee Stock Purchase Plan | Employee Stock
Equity [Line Items]
Purchase price of common stock						85.00%
Employee Stock Purchase Plan | United States
Equity [Line Items]
Number of employee stock purchase plans | employee_stock_purchase_plan						1
Employee Stock Purchase Plan | Non-US
Equity [Line Items]
Number of employee stock purchase plans | employee_stock_purchase_plan						1