Fair Value of Financial Instruments (Details) - Senior Notes - USD ($)	Sep. 30, 2020	Sep. 01, 2020	Jun. 22, 2020
$300 0.450% senior notes due 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Face amount of debt		$ 300,000,000.0
Fixed interest rate		0.45%
$700 1.000% senior notes due 2025
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Face amount of debt		$ 700,000,000.0
Fixed interest rate		1.00%
$700 1.400% senior notes due 2027
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Face amount of debt		$ 700,000,000.0
Fixed interest rate		1.40%
$600 2.000% senior notes due 2030
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Face amount of debt			$ 600,000,000.0
Fixed interest rate			2.00%
$1,000 1.750% senior notes due 2031
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Face amount of debt		$ 1,000,000,000.0
Fixed interest rate		1.75%
Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed rate senior notes carrying amount	$ 8,600,000,000
Fair Value, Inputs, Level 2 | $600 3.000% senior notes due 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Face amount of debt	$ 600,000,000
Fixed interest rate	3.00%
Long-term debt, fair value	$ 602,000,000
Fair Value, Inputs, Level 2 | $500 2.800% senior notes due 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Face amount of debt	$ 500,000,000
Fixed interest rate	2.80%
Long-term debt, fair value	$ 513,000,000
Fair Value, Inputs, Level 2 | $500 3.125% senior notes due 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Face amount of debt	$ 500,000,000
Fixed interest rate	3.125%
Long-term debt, fair value	$ 524,000,000
Fair Value, Inputs, Level 2 | $300 0.450% senior notes due 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Face amount of debt	$ 300,000,000
Fixed interest rate	0.45%
Long-term debt, fair value	$ 300,000,000
Fair Value, Inputs, Level 2 | $700 3.650% senior notes due 2023
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Face amount of debt	$ 700,000,000
Fixed interest rate	3.65%
Long-term debt, fair value	$ 761,000,000
Fair Value, Inputs, Level 2 | $500 2.350% senior notes due 2024
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Face amount of debt	$ 500,000,000
Fixed interest rate	2.35%
Long-term debt, fair value	$ 529,000,000
Fair Value, Inputs, Level 2 | $300 3.850% senior notes due 2025
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Face amount of debt	$ 300,000,000
Fixed interest rate	3.85%
Long-term debt, fair value	$ 342,000,000
Fair Value, Inputs, Level 2 | $700 1.000% senior notes due 2025
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Face amount of debt	$ 700,000,000
Fixed interest rate	1.00%
Long-term debt, fair value	$ 702,000,000
Fair Value, Inputs, Level 2 | $700 3.800% senior notes due 2026
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Face amount of debt	$ 700,000,000
Fixed interest rate	3.80%
Long-term debt, fair value	$ 808,000,000
Fair Value, Inputs, Level 2 | $700 1.400% senior notes due 2027
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Face amount of debt	$ 700,000,000
Fixed interest rate	1.40%
Long-term debt, fair value	$ 708,000,000
Fair Value, Inputs, Level 2 | $800 4.200% senior notes due 2028
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Face amount of debt	$ 800,000,000
Fixed interest rate	4.20%
Long-term debt, fair value	$ 954,000,000
Fair Value, Inputs, Level 2 | $700 2.950% senior notes due 2029
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Face amount of debt	$ 700,000,000
Fixed interest rate	2.95%
Long-term debt, fair value	$ 770,000,000
Fair Value, Inputs, Level 2 | $600 2.000% senior notes due 2030
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Face amount of debt	$ 600,000,000
Fixed interest rate	2.00%
Long-term debt, fair value	$ 612,000,000
Fair Value, Inputs, Level 2 | $1,000 1.750% senior notes due 2031
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Face amount of debt	$ 1,000,000,000
Fixed interest rate	1.75%
Long-term debt, fair value	$ 1,000,000,000