Leases Lease Disclosure (Details)	12 Months Ended
	Dec. 31, 2017 Property Restaurant
Property Subject to or Available for Operating Lease
Number of Restaurants | Restaurant	6,634
Minimum
Property Subject to or Available for Operating Lease
Lessee Leasing Arrangements, Operating Leases, Term of Contract	15 years
Maximum
Property Subject to or Available for Operating Lease
Lessee Leasing Arrangements, Operating Leases, Term of Contract	20 years
Lessee Disclosure | Minimum
Property Subject to or Available for Operating Lease
Lessee Leasing Arrangements, Operating Leases, Term of Contract	15 years
Lessee Disclosure | Maximum
Property Subject to or Available for Operating Lease
Lessee Leasing Arrangements, Operating Leases, Term of Contract	20 years
Lessee Disclosure | Land and Building
Property Subject to or Available for Operating Lease
Property Subject to or Available for Operating Lease, Number of Units	146
Lessee Disclosure | Property Subject to Operating Lease | Land and Building
Property Subject to or Available for Operating Lease
Property Subject to or Available for Operating Lease, Number of Units	50
Lessee Disclosure | Property Subject to Operating Lease | Land
Property Subject to or Available for Operating Lease
Property Subject to or Available for Operating Lease, Number of Units	141
Lessor Disclosure
Property Subject to or Available for Operating Lease
Lessor Leasing Arrangements, Operating Leases, Term of Contract	20 years
Lessor Disclosure | Property Subject to Operating Lease
Property Subject to or Available for Operating Lease
Property Subject to or Available for Operating Lease, Number of Units	1,296
Lessor Disclosure | Property Subject to Operating Lease | Assets Leased to Others
Property Subject to or Available for Operating Lease
Property Subject to or Available for Operating Lease, Number of Units	521
Entity Operated Units
Property Subject to or Available for Operating Lease
Number of Restaurants | Restaurant	337