Indebtedness - Fair Value and Carrying Value of Long-Term Debt (Detail) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Debt Instrument [Line Items]
Carrying Amount	$ 7,786	$ 7,413
Estimated Fair Value	$ 7,755	$ 7,982
4.875% 2013 Senior Notes, due 2024
Debt Instrument [Line Items]
Notes payable, interest rate	4.875%	4.875%
Carrying Amount	$ 498	$ 498
Estimated Fair Value	$ 516	$ 538
5.25% 2014 Senior Notes, due 2044
Debt Instrument [Line Items]
Notes payable, interest rate	5.25%	5.25%
Carrying Amount	$ 574	$ 591
Estimated Fair Value	$ 697	$ 805
1.75% 2015 Senior Notes, due 2027
Debt Instrument [Line Items]
Notes payable, interest rate	1.75%	1.75%
Carrying Amount	$ 554	$ 566
Estimated Fair Value	$ 565	$ 607
2.625% 2017 Senior Notes, due 2023
Debt Instrument [Line Items]
Notes payable, interest rate	2.625%	2.625%
Carrying Amount	$ 501	$ 504
Estimated Fair Value	$ 502	$ 509
3.25% 2017 Senior Notes, due 2028
Debt Instrument [Line Items]
Notes payable, interest rate	3.25%	3.25%
Carrying Amount	$ 479	$ 503
Estimated Fair Value	$ 501	$ 539
4.25% 2018 Senior Notes, due 2029
Debt Instrument [Line Items]
Notes payable, interest rate	4.25%	4.25%
Carrying Amount	$ 384	$ 396
Estimated Fair Value	$ 420	$ 451
4.875% 2018 Senior Notes, due 2048
Debt Instrument [Line Items]
Notes payable, interest rate	4.875%	4.875%
Carrying Amount	$ 365	$ 383
Estimated Fair Value	$ 457	$ 526
0.950% Senior Notes Due 2030
Debt Instrument [Line Items]
Notes payable, interest rate	0.95%	0.95%
Carrying Amount	$ 828	$ 846
Estimated Fair Value	$ 787	$ 866
3.75% 2020 Senior Notes, due 2025
Debt Instrument [Line Items]
Notes payable, interest rate	3.75%	3.75%
Carrying Amount	$ 676	$ 686
Estimated Fair Value	$ 713	$ 750
3.25% 2020 Senior Notes, due 2050
Debt Instrument [Line Items]
Notes payable, interest rate	3.25%	3.25%
Carrying Amount	$ 293	$ 293
Estimated Fair Value	$ 269	$ 311
2.55% 2020 Senior Notes, due 2060
Debt Instrument [Line Items]
Notes payable, interest rate	2.55%	2.55%
Carrying Amount	$ 491	$ 491
Estimated Fair Value	$ 370	$ 432
2.00% 2021 Senior Notes, due 2031
Debt Instrument [Line Items]
Notes payable, interest rate	2.00%	2.00%
Carrying Amount	$ 587	$ 587
Estimated Fair Value	$ 531	$ 581
2.75% 2021 Senior Notes, due 2041
Debt Instrument [Line Items]
Notes payable, interest rate	2.75%	2.75%
Carrying Amount	$ 582	$ 581
Estimated Fair Value	$ 515	$ 579
3.10% 2021 Senior Notes, due 2061
Debt Instrument [Line Items]
Notes payable, interest rate	3.10%	3.10%
Carrying Amount	$ 488	$ 488
Estimated Fair Value	$ 420	$ 488
3.75% 2022 Senior Notes, due 2052
Debt Instrument [Line Items]
Notes payable, interest rate	3.75%
Carrying Amount	$ 486
Estimated Fair Value	$ 492