Segments - Schedule of Segment Reporting Information by Segment (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Segment Reporting Information [Line Items]
Rental revenues	$ 29,066	$ 27,382	$ 57,873	$ 53,524
Total revenues	237,794	233,619	468,217	437,818
Interest expense	17,200	17,800	34,700	36,500
Depreciation and amortization	10,000	10,000	19,969	19,976
Pretax book income (loss)	32,531	38,658	66,688	62,672
Operating Segments
Segment Reporting Information [Line Items]
Pretax book income (loss)	95,700	98,900	188,400	184,200
Corporate
Segment Reporting Information [Line Items]
Interest expense	15,400	15,700	30,900	32,200
Depreciation and amortization	3,000	2,900	5,900	5,900
Pretax book income (loss)	(63,200)	(60,200)	(121,800)	(121,500)
Franchise operations | Operating Segments
Segment Reporting Information [Line Items]
Depreciation and amortization	2,500	2,500	5,000	5,000
Pretax book income (loss)	86,000	87,700	169,200	163,700
Rental operations | Operating Segments
Segment Reporting Information [Line Items]
Rental revenues	29,100	27,400	57,900	53,500
Interest expense	1,000	1,300	2,200	2,600
Depreciation and amortization	2,600	2,800	5,300	5,600
Pretax book income (loss)	7,200	6,800	13,900	12,000
Company restaurants | Operating Segments
Segment Reporting Information [Line Items]
Interest expense	800	800	1,600	1,700
Depreciation and amortization	1,900	1,800	3,800	3,500
Pretax book income (loss)	1,600	3,400	3,600	6,500
Financing operations | Operating Segments
Segment Reporting Information [Line Items]
Pretax book income (loss)	900	1,000	1,700	2,000
Franchise Revenue:
Segment Reporting Information [Line Items]
Revenue from contract with customer	168,259	166,954	329,491	307,930
Franchise Revenue: | Franchise operations | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contract with customer	168,300	166,900	329,500	307,900
Company restaurants
Segment Reporting Information [Line Items]
Revenue from contract with customer		38,194	78,927	74,143
Company restaurants | Company restaurants
Segment Reporting Information [Line Items]
Revenue from contract with customer	39,511	38,200	78,900	74,200
Financing revenues
Segment Reporting Information [Line Items]
Revenue from contract with customer	958	1,089	1,926	2,221
Financing revenues | Financing operations | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contract with customer	$ 900	$ 1,100	$ 1,900	$ 2,200