Segment Reporting - Financial Information by Segment (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Segment Reporting Information [Line Items]
Total revenue	$ 170,385	$ 89,858
Operating expenses	50,849	30,298
Selling, general and administrative expenses	37,403	25,729
Other income, net	(2,866)	(3,013)
Segment profit (loss)	32,006	1,751
Depreciation and amortization	35,675	28,214
Loss on disposal of assets, net	232	51
Change in fair value of private placement warrants	3,734	2,067
Stock-based compensation	4,446	2,908
Interest expense, net	14,279	9,164
Loss on extinguishment of debt	0	5,334
Income (loss) before income taxes	16,859	(11,801)
Service Revenue
Segment Reporting Information [Line Items]
Total revenue	161,134	89,763
Cost of revenue	3,779	880
Product Sales
Segment Reporting Information [Line Items]
Total revenue	9,251	95
Cost of revenue	5,995	27
Operating Segments
Segment Reporting Information [Line Items]
Segment profit (loss)	75,225	35,937
Operating Segments | Government Solutions
Segment Reporting Information [Line Items]
Total revenue	78,828	44,169
Operating expenses	32,391	16,092
Selling, general and administrative expenses	16,455	10,811
Other income, net	72	(943)
Segment profit (loss)	25,710	17,833
Loss on disposal of assets, net	241	51
Income (loss) before income taxes	25,469	17,782
Operating Segments | Commercial Services
Segment Reporting Information [Line Items]
Total revenue	73,465	45,689
Operating expenses	15,947	14,206
Selling, general and administrative expenses	13,276	10,792
Other income, net	(2,955)	(2,070)
Segment profit (loss)	46,595	22,230
Income (loss) before income taxes	46,595	22,230
Operating Segments | Parking Solutions [Member]
Segment Reporting Information [Line Items]
Total revenue	18,092
Operating expenses	2,511
Selling, general and administrative expenses	7,672
Other income, net	17
Segment profit (loss)	2,920
Loss on disposal of assets, net	(9)
Income (loss) before income taxes	2,929
Operating Segments | Service Revenue | Government Solutions
Segment Reporting Information [Line Items]
Total revenue	73,224	44,074
Cost of revenue	473	349
Operating Segments | Service Revenue | Commercial Services
Segment Reporting Information [Line Items]
Total revenue	73,465	45,689
Cost of revenue	602	531
Operating Segments | Service Revenue | Parking Solutions [Member]
Segment Reporting Information [Line Items]
Total revenue	14,445
Cost of revenue	2,704
Operating Segments | Product Sales | Government Solutions
Segment Reporting Information [Line Items]
Total revenue	5,604	95
Cost of revenue	3,727	27
Operating Segments | Product Sales | Parking Solutions [Member]
Segment Reporting Information [Line Items]
Total revenue	3,647
Cost of revenue	2,268
Corporate and Other
Segment Reporting Information [Line Items]
Selling, general and administrative expenses		4,126
Segment profit (loss)		(4,126)
Depreciation and amortization	35,675	28,214
Change in fair value of private placement warrants	3,734	2,067
Stock-based compensation	4,446	2,908
Interest expense, net	14,279	9,164
Loss on extinguishment of debt		5,334
Income (loss) before income taxes	$ (58,134)	$ (51,813)