Long-Term Debt (Details) - Notes Payable - USD ($)	6 Months Ended
	Jun. 30, 2020	May 31, 2020
Debt Instrument [Line Items]
Extinguishment of debt, amount	$ 3,800,000,000
Floating Rate Notes due 2023
Debt Instrument [Line Items]
Debt instrument, face amount		$ 300,000,000
1.141% Notes due 2023
Debt Instrument [Line Items]
Debt instrument, face amount		$ 1,200,000,000
Debt instrument, interest rate, stated percentage		1.141%
1.554% Notes due 2025
Debt Instrument [Line Items]
Debt instrument, face amount		$ 2,500,000,000
Debt instrument, interest rate, stated percentage		1.554%
1.995% Notes due 2027
Debt Instrument [Line Items]
Debt instrument, face amount		$ 1,000,000,000.0
Debt instrument, interest rate, stated percentage		1.995%
2.236% Notes due 2030
Debt Instrument [Line Items]
Debt instrument, face amount		$ 1,500,000,000
Debt instrument, interest rate, stated percentage		2.236%
2.978% Notes due 2040
Debt Instrument [Line Items]
Debt instrument, face amount		$ 500,000,000
Debt instrument, interest rate, stated percentage		2.978%
3.078% Notes due 2050
Debt Instrument [Line Items]
Debt instrument, face amount		$ 1,000,000,000.0
Debt instrument, interest rate, stated percentage		3.078%