Revenue Recognition - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Revenue	$ 187,232	$ 201,246
Restaurant | Point in Time
Disaggregation of Revenue [Line Items]
Revenue	93,857	101,260
Restaurant | Over Time
Disaggregation of Revenue [Line Items]
Revenue	29,450	32,809
Restaurant | Restaurant | Point in Time
Disaggregation of Revenue [Line Items]
Revenue	92,702	98,353
Restaurant | Restaurant | Over Time
Disaggregation of Revenue [Line Items]
Revenue	27,224	29,713
Restaurant | Grocery | Point in Time
Disaggregation of Revenue [Line Items]
Revenue	1,155	2,907
Restaurant | Grocery | Over Time
Disaggregation of Revenue [Line Items]
Revenue	2,226	3,096
Restaurant | Mission Systems | Point in Time
Disaggregation of Revenue [Line Items]
Revenue	0	0
Restaurant | Mission Systems | Over Time
Disaggregation of Revenue [Line Items]
Revenue	0	0
Restaurant | ISR Solutions | Point in Time
Disaggregation of Revenue [Line Items]
Revenue	0	0
Restaurant | ISR Solutions | Over Time
Disaggregation of Revenue [Line Items]
Revenue	0	0
Government | Over Time
Disaggregation of Revenue [Line Items]
Revenue	63,925	67,177
Government | Restaurant | Over Time
Disaggregation of Revenue [Line Items]
Revenue	0	0
Government | Grocery | Over Time
Disaggregation of Revenue [Line Items]
Revenue	0	0
Government | Mission Systems | Over Time
Disaggregation of Revenue [Line Items]
Revenue	33,512	34,796
Government | ISR Solutions | Over Time
Disaggregation of Revenue [Line Items]
Revenue	$ 30,413	$ 32,381