Basis of Presentation and Consolidation - Additional Information (Details) $ in Millions	6 Months Ended		12 Months Ended
	Jun. 30, 2019 USD ($) Restaurant	Jun. 30, 2018 USD ($)	Dec. 31, 2018 Restaurant
Summary Of Accounting Policies [Line Items]
Tenant inducements paid to franchisees | $	$ 8	$ 13
Restaurant VIEs
Summary Of Accounting Policies [Line Items]
Number of VIE consolidated restaurants | Restaurant	30		17