Segment Reporting - Financial Information by Segment (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Segment Reporting Information [Line Items]
Total revenue	$ 187,487	$ 128,657	$ 357,872	$ 218,515
Operating expenses	54,912	36,186	105,761	66,484
Selling, general and administrative expenses	35,870	22,904	73,273	48,633
Other income, net	(4,039)	(2,798)	(6,905)	(5,811)
Segment profit (loss)	45,161	31,506	77,167	33,257
Depreciation and amortization	34,540	27,013	70,215	55,227
Loss on disposal of assets, net	(399)	1	(631)	(50)
Change in fair value of private placement warrants	(6,600)	8,067	(2,866)	10,134
Tax receivable agreement liability adjustment	(965)	1,661	(965)	1,661
Stock-based compensation	4,566	3,573	9,012	6,481
Interest expense, net	14,485	11,680	28,764	20,844
Loss on extinguishment of debt			0	5,334
Income (loss) before income taxes	42,280	12,896	59,139	1,095
Service Revenue
Segment Reporting Information [Line Items]
Total revenue	174,502	116,426	335,636	206,189
Cost of revenue	3,713	1,332	7,492	2,212
Product Sales
Segment Reporting Information [Line Items]
Total revenue	12,985	12,231	22,236	12,326
Cost of revenue	8,326	6,144	14,321	6,171
Operating Segments
Segment Reporting Information [Line Items]
Segment profit (loss)	88,705	64,889	163,930	100,826
Operating Segments | Government Solutions
Segment Reporting Information [Line Items]
Total revenue	83,528	62,177	162,356	106,346
Operating expenses	34,401	20,196	66,792	36,288
Selling, general and administrative expenses	14,433	10,119	30,888	20,930
Other income, net	218	204	146	1,147
Segment profit (loss)	29,456	25,495	55,166	43,328
Loss on disposal of assets, net	(385)	1	(626)	(50)
Income (loss) before income taxes	29,071	25,496	54,540	43,278
Operating Segments | Commercial Services
Segment Reporting Information [Line Items]
Total revenue	84,888	66,480	158,353	112,169
Operating expenses	18,105	15,990	34,052	30,196
Selling, general and administrative expenses	13,681	9,479	26,957	20,271
Other income, net	3,840	2,594	6,795	4,664
Segment profit (loss)	56,446	42,700	103,041	64,930
Income (loss) before income taxes	56,446	42,700	103,041	64,930
Operating Segments | Parking Solutions [Member]
Segment Reporting Information [Line Items]
Total revenue	19,071		37,163
Operating expenses	2,406		4,917
Selling, general and administrative expenses	7,756		15,428
Other income, net	(19)		(36)
Segment profit (loss)	2,803		5,723
Loss on disposal of assets, net	(14)		(5)
Income (loss) before income taxes	2,789		5,718
Operating Segments | Service Revenue | Government Solutions
Segment Reporting Information [Line Items]
Total revenue	74,672	49,946	147,896	94,020
Cost of revenue	563	427	1,036	776
Operating Segments | Service Revenue | Commercial Services
Segment Reporting Information [Line Items]
Total revenue	84,888	66,480	158,353	112,169
Cost of revenue	496	905	1,098	1,436
Operating Segments | Service Revenue | Parking Solutions [Member]
Segment Reporting Information [Line Items]
Total revenue	14,942		29,387
Cost of revenue	2,654		5,358
Operating Segments | Product Sales | Government Solutions
Segment Reporting Information [Line Items]
Total revenue	8,856	12,231	14,460	12,326
Cost of revenue	4,893	6,144	8,620	6,171
Operating Segments | Product Sales | Parking Solutions [Member]
Segment Reporting Information [Line Items]
Total revenue	4,129		7,776
Cost of revenue	3,433		5,701
Corporate and Other
Segment Reporting Information [Line Items]
Selling, general and administrative expenses		3,306		7,432
Segment profit (loss)		(3,306)		(7,432)
Depreciation and amortization	34,540	27,013	70,215	55,227
Change in fair value of private placement warrants	6,600	8,067	(2,866)	10,134
Tax receivable agreement liability adjustment	(965)	1,661	(965)	1,661
Stock-based compensation	4,566	3,573	9,012	6,481
Interest expense, net	14,485	11,680	28,764	20,844
Loss on extinguishment of debt				5,334
Income (loss) before income taxes	$ (46,026)	$ (55,300)	$ (104,160)	$ (107,113)