Funds Receivable and Customer Accounts and Investments - Schedule of Adjustments to Carrying Value of Equity Investments (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Equity Securities without Readily Determinable Fair Value [Roll Forward]
Carrying amount, beginning of period	$ 293	$ 88
Adjustments related to non-marketable equity securities:
Net additions	60	119
Gross unrealized gains	144	91
Gross unrealized losses and impairments	0	(5)
Carrying amount, end of period	$ 497	$ 293