Segment and Related Information - Summary of Segment Information (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($) segment	Sep. 30, 2019 USD ($)
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	$ 54,847	$ 45,380	$ 155,270	$ 134,309
Operating loss	(998)	(3,991)	(12,171)	(9,545)
Other expense, net	(486)	(401)	(1,250)	(1,205)
Interest expense, net	(2,235)	(1,588)	(6,318)	(2,978)
Loss on extinguishment of debt	0	0	(8,123)	0
Loss before benefit from income taxes	(3,719)	(5,980)	(27,862)	(13,728)
Depreciation, amortization and accretion	3,452	1,872	10,152	4,993
Capital expenditures including software costs	2,015	1,318	7,061	4,635
United States
Information as to the Company's segments [Abstract]
Revenue	51,036	44,380	148,293	127,962
Other Countries
Information as to the Company's segments [Abstract]
Revenue	3,811	1,000	6,977	6,347
Restaurant/Retail
Information as to the Company's segments [Abstract]
Revenue	37,347	29,841	102,389	87,663
Government
Information as to the Company's segments [Abstract]
Revenue	17,500	15,539	52,881	46,646
Operating segments | Restaurant/Retail
Information as to the Company's segments [Abstract]
Operating loss	(2,763)	(4,432)	(16,530)	(12,029)
Depreciation, amortization and accretion	1,984	824	5,790	2,893
Capital expenditures including software costs	1,324	838	5,814	2,679
Operating segments | Government
Information as to the Company's segments [Abstract]
Operating loss	1,774	809	4,302	3,690
Depreciation, amortization and accretion	80	17	136	54
Capital expenditures including software costs	415	0	849	176
Other
Information as to the Company's segments [Abstract]
Operating loss	(9)	(368)	57	(1,206)
Depreciation, amortization and accretion	1,388	1,031	4,226	2,046
Capital expenditures including software costs	$ 276	$ 480	$ 398	$ 1,780