Income Taxes - Schedule of Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Changes in unrecognized tax benefits
Gross amounts of unrecognized tax benefits as of the beginning of the period	$ 800	$ 424	$ 312
Increases related to prior period tax positions	97	120	61
Decreases related to prior period tax positions	(28)	(6)	(23)
Increases related to current period tax positions	336	287	112
Settlements	(63)	(20)	(35)
Statute of limitation expirations	(1)	(5)	(3)
Gross amounts of unrecognized tax benefits as of the end of the period	$ 1,141	$ 800	$ 424