Income Taxes - Unrecognized Tax Benefits - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Contingency [Line Items]
Unrecognized tax balance	$ 551	$ 487	$ 458	$ 440
Unrecognized tax benefits that would impact effective tax rate	466
Interest and penalties, net of tax benefits, in uncertain tax positions	14
Unrecognized tax benefits, interest and penalties accrued	61	$ 43
Decrease in unrecognized tax benefits is reasonably possible	196
Paypal
Income Tax Contingency [Line Items]
Unrecognized tax balance	100
Unrecognized tax benefits that would impact effective tax rate	$ 95