Commercial Paper and Long-Term Debt Subsequent Events (Details) - USD ($) $ in Millions	Jul. 31, 2019	Jun. 30, 2019	Dec. 31, 2018
Subsequent Event [Line Items]
Par Value		$ 41,401	$ 35,667
Subsequent Event [Member]
Subsequent Event [Line Items]
Par Value	$ 5,500
2.375% notes due August 2024 [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.375%
Par Value	$ 750
2.875% notes due August 2029 [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.875%
Par Value	$ 1,000
3.500% notes due 2039 [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.50%
Par Value	$ 1,250
3.700% notes due August 2049 [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.70%
Par Value	$ 1,250
3.875% notes due August 2059 [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.875%
Par Value	$ 1,250