Significant Accounting Policies - Additional Information (Details)	3 Months Ended		12 Months Ended
	Mar. 31, 2022 USD ($) Customer	Mar. 31, 2021 USD ($) Customer	Dec. 31, 2021 USD ($)
Summary Of Significant Accounting Principles And Policies [Line Items]
Net income (loss)	$ 10,040,000	$ (8,915,000)
Additional paid-in capital	312,986,000		$ 309,883,000
Accumulated deficit	(71,376,000)		(81,416,000)
Revenue	170,385,000	89,858,000
Interest or late fees charged on delinquent accounts	0
Deferred Revenue, Revenue Recognized	3,500,000
Product Sales
Summary Of Significant Accounting Principles And Policies [Line Items]
Revenue	9,251,000	95,000
Service Revenue
Summary Of Significant Accounting Principles And Policies [Line Items]
Revenue	161,134,000	$ 89,763,000
Parking Solutions
Summary Of Significant Accounting Principles And Policies [Line Items]
Deferred Revenue	20,000,000.0		20,900,000
Government Solutions and Parking Solutions customers
Summary Of Significant Accounting Principles And Policies [Line Items]
Deferred Revenue	$ 10,000,000.0		$ 8,900,000
Customer Concentration Risk | Sales Revenue | Parking Solutions
Summary Of Significant Accounting Principles And Policies [Line Items]
Number of customers exceeds 10% | Customer	0
Customer Concentration Risk | Sales Revenue | Government Solutions
Summary Of Significant Accounting Principles And Policies [Line Items]
Number of customers exceeds 10% | Customer	10	10
Customer Concentration Risk | Sales Revenue | Minimum
Summary Of Significant Accounting Principles And Policies [Line Items]
Concentration risk percentage	10.00%
Customer Concentration Risk | Accounts Receivable | City of New York Department of Transportation
Summary Of Significant Accounting Principles And Policies [Line Items]
Concentration risk percentage	29.00%		39.00%
Customer Concentration Risk | Accounts Receivable | Commercial Services
Summary Of Significant Accounting Principles And Policies [Line Items]
Number of customers exceeds 10% | Customer	0	0
Customer Concentration Risk | Accounts Receivable | Minimum
Summary Of Significant Accounting Principles And Policies [Line Items]
Concentration risk percentage	10.00%