Revenue Recognition - Schedule of Performance Obligations (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2018	Dec. 31, 2017
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue recognized included in contract liabilities at beginning of period	$ 4,800	$ 7,700
Current - under one year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations	10,235	10,235	$ 6,784
Non-current - over one year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations	4,641	4,641	2,668
Restaurant | Current - under one year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations	10,188	10,188	6,199
Restaurant | Non-current - over one year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations	4,641	4,641	2,668
Government | Current - under one year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations	47	47	585
Government | Non-current - over one year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations	$ 0	$ 0	$ 0