Segment and Related Information - Summary of Segment Information (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($) segment	Jun. 30, 2019 USD ($)
Segment and Related Information [Abstract]
Number of operating segments | segment			2
Number of reportable segments | segment			2
Information as to the Company's segments [Abstract]
Revenue	$ 45,691	$ 44,247	$ 100,423	$ 88,929
Operating loss	(5,718)	(3,453)	(11,173)	(5,554)
Other expense	(139)	(374)	(764)	(804)
Interest expense, net	(2,111)	(1,244)	(4,083)	(1,390)
Loss on extinguishment of debt	0	0	(8,123)	0
Loss before benefit from (provision for) income taxes	(7,968)	(5,071)	(24,143)	(7,748)
Depreciation, amortization and accretion	3,558	2,109	6,700	3,121
Capital expenditures including software costs	3,006	1,394	5,046	3,317
United States
Information as to the Company's segments [Abstract]
Revenue	44,626	41,657	97,257	83,582
Other Countries
Information as to the Company's segments [Abstract]
Revenue	1,065	2,590	3,166	5,347
Restaurant/Retail
Information as to the Company's segments [Abstract]
Revenue	27,633	28,262	65,042	57,822
Government
Information as to the Company's segments [Abstract]
Revenue	18,058	15,985	35,381	31,107
Operating segments | Restaurant/Retail
Information as to the Company's segments [Abstract]
Operating loss	(7,697)	(4,615)	(13,767)	(7,597)
Depreciation, amortization and accretion	1,951	1,201	3,806	2,069
Capital expenditures including software costs	2,783	778	4,490	1,841
Operating segments | Government
Information as to the Company's segments [Abstract]
Operating loss	1,349	1,518	2,528	2,881
Depreciation, amortization and accretion	40	18	56	37
Capital expenditures including software costs	223	0	434	176
Other
Information as to the Company's segments [Abstract]
Operating loss	630	(356)	66	(838)
Depreciation, amortization and accretion	1,567	890	2,838	1,015
Capital expenditures including software costs	$ 0	$ 616	$ 122	$ 1,300