Goodwill - Changes In Carrying Amount of Goodwill (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Jun. 30, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Goodwill [Roll Forward]
Goodwill, beginning balance		$ 343,862	$ 345,300	$ 339,200
Business acquisition				6,100
Purchase price adjustment related to business acquisition			(1,500)
Impairment loss	$ (92,200)	(92,200)
Goodwill, ending balance		251,628	343,862	345,300
Applebee's | Franchised
Goodwill [Roll Forward]
Goodwill, beginning balance		328,400	328,400	328,400
Business acquisition				0
Purchase price adjustment related to business acquisition			0
Impairment loss		(92,200)
Goodwill, ending balance		236,200	328,400	328,400
Applebee's | Entity Operated Units
Goodwill [Roll Forward]
Goodwill, beginning balance		4,600	6,100	0
Business acquisition				6,100
Purchase price adjustment related to business acquisition			(1,500)
Impairment loss		0
Goodwill, ending balance		4,600	4,600	6,100
IHOP | Franchised
Goodwill [Roll Forward]
Goodwill, beginning balance		10,800	10,800	10,800
Business acquisition				0
Purchase price adjustment related to business acquisition			0
Impairment loss		0
Goodwill, ending balance		$ 10,800	$ 10,800	$ 10,800