Fair Value Measurements - Schedule of Carrying Values and Estimated Fair Values of Debt Instruments (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Amount	$ 14,178	$ 13,918
Fair value	13,636,000
Commercial Paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Amount	1,268
Fair value	1,270,000
Other short-term debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Amount	9
Fair value	$ 9,000
2022 Senior Notes (2.35% senior unsecured notes due September 15, 2022) | Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate, stated percentage	2.35%
2022 Senior Notes (2.35% senior unsecured notes due September 15, 2022) | Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Amount	$ 500
Fair value	$ 502,000
2023 Senior Notes (0.70% senior unsecured notes due June 15, 2023) | Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate, stated percentage	0.70%
Carrying Amount	$ 998
Fair value	$ 985,000
2023 Senior Notes (3.45% senior unsecured notes due September 21, 2023) | Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate, stated percentage	3.45%
Carrying Amount	$ 399
Fair value	$ 405,000
2023 Senior Notes (4.00% senior unsecured notes due October 15, 2023) | Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate, stated percentage	4.00%
Carrying Amount	$ 798
Fair value	$ 818,000
2025 Senior Notes (3.75% senior unsecured notes due December 1, 2025) | Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate, stated percentage	3.75%
Carrying Amount	$ 1,246
Fair value	$ 1,281,000
2027 Senior Notes (3.10% senior unsecured notes due September 15, 2027) | Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate, stated percentage	3.10%
Carrying Amount	$ 497
Fair value	$ 499,000
2028 Senior Notes (3.75% senior unsecured notes due September 21, 2028) | Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate, stated percentage	3.75%
Carrying Amount	$ 594
Fair value	$ 614,000
2030 Senior Notes (2.10% senior unsecured notes due June 15, 2030) | Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate, stated percentage	2.10%
Carrying Amount	$ 1,235
Fair value	$ 1,147,000
2032 Senior Notes (1.85% senior unsecured notes due September 15, 2032) | Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate, stated percentage	1.85%
Carrying Amount	$ 1,483
Fair value	$ 1,301,000
2040 Senior Notes (2.65% senior unsecured notes due September 15, 2040) | Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate, stated percentage	2.65%
Carrying Amount	$ 1,230
Fair value	$ 1,074,000
2048 Senior Notes (4.25% senior unsecured notes due September 21, 2048) | Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate, stated percentage	4.25%
Carrying Amount	$ 1,231
Fair value	$ 1,357,000
2050 Senior Notes (3.00% senior unsecured notes due June 15, 2050) | Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate, stated percentage	3.00%
Carrying Amount	$ 1,220
Fair value	$ 1,097,000
2060 Senior Notes (3.00% senior unsecured notes due September 15, 2060) | Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate, stated percentage	3.00%
Carrying Amount	$ 1,470
Fair value	$ 1,277,000