Segment and Related Information, Reconciliation of Segment Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Identifiable assets by geographic area [Abstract]
Identifiable assets	$ 105,048	$ 94,681
Goodwill by business segment [Abstract]
Goodwill	11,051	11,051
Restaurant/Retail
Goodwill by business segment [Abstract]
Goodwill	10,300	10,300
Government
Goodwill by business segment [Abstract]
Goodwill	800	800
Operating segments | Restaurant/Retail
Identifiable assets by geographic area [Abstract]
Identifiable assets	73,255	68,004
Goodwill by business segment [Abstract]
Goodwill	10,315	10,315
Operating segments | Government
Identifiable assets by geographic area [Abstract]
Identifiable assets	13,487	9,867
Goodwill by business segment [Abstract]
Goodwill	736	736
Reportable geographical components | United States
Identifiable assets by geographic area [Abstract]
Identifiable assets	95,105	84,652
Reportable geographical components | Other Countries
Identifiable assets by geographic area [Abstract]
Identifiable assets	9,943	10,029
Other
Identifiable assets by geographic area [Abstract]
Identifiable assets	$ 18,306	$ 16,810