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Identifiable Intangible Assets and Goodwill - Additional Information (Details)	3 Months Ended		12 Months Ended
	Mar. 31, 2020 USD ($) segment	Mar. 31, 2019 USD ($)	Dec. 31, 2019 USD ($)	Dec. 18, 2019 USD ($)
Finite-Lived Intangible Assets [Line Items]
Research and development	$ 4,865,000	$ 3,060,000
Capitalized software development costs	1,800,000	1,000,000
Amortization of capitalized software development costs	1,600,000	500,000
Amortization of identifiable intangible assets	$ 210,000	0
Number of operating segments \| segment	2
Goodwill	$ 41,386,000		$ 41,386,000
Goodwill impairment charge	0	0
Restaurant/Retail And Government Reporting Segments
Finite-Lived Intangible Assets [Line Items]
Goodwill	41,400,000		41,400,000
Brink Acquisition
Finite-Lived Intangible Assets [Line Items]
Amortization of identifiable intangible assets	200,000	$ 200,000
3M's Drive-Thru Communications Systems
Finite-Lived Intangible Assets [Line Items]
Amortization of identifiable intangible assets	200,000
Restaurant Magic
Finite-Lived Intangible Assets [Line Items]
Amortization of identifiable intangible assets	$ 600,000
Goodwill				$ 27,945,000
Minimum
Finite-Lived Intangible Assets [Line Items]
Useful life	3 years
Minimum \| Internal use software
Finite-Lived Intangible Assets [Line Items]
Useful life	3 years
Maximum
Finite-Lived Intangible Assets [Line Items]
Useful life	5 years
Maximum \| Internal use software
Finite-Lived Intangible Assets [Line Items]
Useful life	5 years
Internally developed software costs not meeting general release threshold
Finite-Lived Intangible Assets [Line Items]
Research and development	$ 4,400,000		$ 2,500,000