Restaurant Closure Costs and Impairment of Long-Lived Assets (Narrative) (Details) $ in Thousands	1 Months Ended	9 Months Ended
	Jun. 30, 2018 item	Sep. 30, 2018 USD ($) item
Minimum [Member]
Restructuring Cost and Reserve [Line Items]
Restaurant exits costs		$ 37,000
Asset impairment costs		26,000
Loss on lease termination costs		11,000
Number of restaurants expected to be closed | item	55
Maximum [Member]
Restructuring Cost and Reserve [Line Items]
Restaurant exits costs		43,000
Asset impairment costs		27,000
Loss on lease termination costs		$ 16,000
Number of restaurants expected to be closed | item	65
Chipotle [Member]
Restructuring Cost and Reserve [Line Items]
Number of restaurants closed | item		33
Pizzeria Locale [Member]
Restructuring Cost and Reserve [Line Items]
Number of restaurants closed | item		5