Equity Method Investments - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Equity Method Investee
Schedule of Equity Method Investments [Line Items]
Accounts receivable from equity method investments	$ 72		$ 72		$ 47
Wendy's Company TIMWEN Partnership | Tim Hortons
Schedule of Equity Method Investments [Line Items]
Cash distributions	2	$ 3	6	$ 10
Rent expense	4	$ 5	11	$ 14
Carrols Restaurant Group, Inc.
Schedule of Equity Method Investments [Line Items]
Quoted market price	$ 61		$ 61
BK Brasil
Schedule of Equity Method Investments [Line Items]
Ownership percentage	9.80%		9.80%
Quoted market price	$ 43		$ 43
Canada | Wendy's Company TIMWEN Partnership
Schedule of Equity Method Investments [Line Items]
Ownership percentage	50.00%		50.00%
United States | Carrols Restaurant Group, Inc.
Schedule of Equity Method Investments [Line Items]
Ownership percentage	15.20%		15.20%
Other assets, net
Schedule of Equity Method Investments [Line Items]
Equity method investments	$ 198		$ 198		$ 266