REAL ESTATE INVESTMENTS, NET AND INTANGIBLE ASSETS AND LIABILITIES, NET - Real Estate Investments (Details)	12 Months Ended
	Dec. 31, 2020 USD ($) state property restaurant	Dec. 31, 2019 USD ($) property state
Property Subject to or Available for Operating Lease [Line Items]
Number of restaurants | restaurant	309
Number of states in which entity operates | state	46
Real estate investments, contingent consideration	$ 0
Number of properties under ground leases | property	3
Land For Development
Property Subject to or Available for Operating Lease [Line Items]
Payments to acquire land	$ 2,400,000
Incurred capitalized construction costs	800,000
Ground lease
Property Subject to or Available for Operating Lease [Line Items]
Purchase	6,000,000.0
Property Subject to Operating Lease
Property Subject to or Available for Operating Lease [Line Items]
Payments to acquire real estate	$ 227,300,000	$ 205,200,000
Number of restaurants | property	100	90
Number of states in which entity operates | state	29	27
Payments to acquire land	$ 129,500,000	$ 121,500,000
Payments to acquire buildings and improvements	52,600,000	42,700,000
Payments to acquire intangible assets	$ 45,200,000	$ 41,000,000.0
Occupation percent	100.00%	100.00%
Lessee leasing arrangements, operating leases, term of contract	8 years 4 months 24 days	10 years
Number of real estate properties | property		0