Segments (Schedule of Segment Reporting Information by Segment) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Segment Reporting Information [Line Items]
Franchise revenues	$ 151,941	$ 153,064	$ 307,254	$ 307,789
Rental revenues	30,324	30,124	61,165	60,589
Company restaurants	0	3,378	0	7,518
Financing revenues	2,206	2,088	4,215	4,219
Total revenues	184,471	188,654	372,634	380,115
Interest expense	17,800	18,500	35,500	36,700
Depreciation and amortization	7,900	7,700	15,842	15,422
Segment profit	24,596	40,900	47,307	66,909
Operating Segments
Segment Reporting Information [Line Items]
Segment profit	78,600	93,000	162,100	187,300
Operating Segments | Franchise operations
Segment Reporting Information [Line Items]
Franchise revenues	151,900	153,100	307,200	307,800
Depreciation and amortization	2,700	2,700	5,300	5,400
Segment profit	69,000	83,600	142,400	168,100
Operating Segments | Rental operations
Segment Reporting Information [Line Items]
Rental revenues	30,400	30,100	61,200	60,600
Interest expense	2,300	2,600	4,800	5,400
Depreciation and amortization	2,900	3,000	5,800	6,000
Segment profit	7,600	7,500	15,800	15,300
Operating Segments | Company restaurants
Segment Reporting Information [Line Items]
Company restaurants	0	3,400	0	7,500
Interest expense	0	100	0	200
Depreciation and amortization	0	0	0	100
Segment profit	0	(100)	0	(300)
Operating Segments | Financing operations
Segment Reporting Information [Line Items]
Financing revenues	2,200	2,100	4,200	4,200
Segment profit	2,000	2,000	3,900	4,200
Corporate
Segment Reporting Information [Line Items]
Interest expense	15,500	15,800	30,700	31,100
Depreciation and amortization	2,300	2,000	4,700	3,900
Segment profit	$ (54,000)	$ (52,100)	$ (114,800)	$ (120,400)