Revenue Recognition - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Disaggregation of Revenue [Line Items]
Support contract timing	12 months
Customer deposits	$ 1,600	$ 1,800
Performance obligations	11,076	12,478	$ 11,082	$ 12,486
Recognition of revenue	$ 2,603	4,034
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-04-01
Disaggregation of Revenue [Line Items]
Performance obligations, period	12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-04-01
Disaggregation of Revenue [Line Items]
Performance obligations, period	12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-04-01
Disaggregation of Revenue [Line Items]
Performance obligations, period	12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-04-01
Disaggregation of Revenue [Line Items]
Performance obligations, period
Restaurant and Retail
Disaggregation of Revenue [Line Items]
Recognition of revenue	$ 2,600	$ 4,000
Restaurant and Retail | Current | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-04-01
Disaggregation of Revenue [Line Items]
Performance obligation, percentage	78.00%
Restaurant and Retail | Non-current | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-04-01
Disaggregation of Revenue [Line Items]
Performance obligation, percentage	100.00%
Performance obligations, period	60 months
Government Segment
Disaggregation of Revenue [Line Items]
Performance obligations	$ 140,066		150,500
Funded performance obligations	30,200		$ 27,800
Government Segment | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-04-01
Disaggregation of Revenue [Line Items]
Performance obligations	56,238
Government Segment | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-04-01
Disaggregation of Revenue [Line Items]
Performance obligations	47,328
Government Segment | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-04-01
Disaggregation of Revenue [Line Items]
Performance obligations	24,434
Government Segment | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-04-01
Disaggregation of Revenue [Line Items]
Performance obligations	$ 12,066
Minimum
Disaggregation of Revenue [Line Items]
Payment period	30 days
Maximum
Disaggregation of Revenue [Line Items]
Payment period	90 days