Income Taxes - Income Taxes (Details) € in Millions, $ in Millions		3 Months Ended		6 Months Ended		12 Months Ended
	Oct. 04, 2017 EUR (€)	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)
Income Tax Disclosure [Abstract]
Provision for income taxes		$ 984	$ 257	$ 1,729	$ 1,094
Discrete tax benefits				831	706
Cash paid for income taxes, net of refunds		486	283	791	451	$ 1,221	$ 822
Tax contingencies		3,700		3,700		3,700		$ 3,900
Income Tax Examination [Line Items]
Income Taxes Paid, Net		$ 486	$ 283	$ 791	$ 451	$ 1,221	$ 822
Luxembourg Tax Administration [Member] | Foreign Tax Authority [Member]
Income Tax Examination [Line Items]
Tax examination, estimate of additional tax expense | €	€ 250