Condensed Consolidated Statements of Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Services revenue	$ 404.4	$ 311.6	$ 1,135.2	$ 834.0
Cost of services (exclusive of depreciation and amortization)	346.2	265.6	966.8	703.2
General and administrative expenses	27.2	21.1	78.4	64.1
Depreciation and amortization	7.2	6.0	20.5	18.5
Operating income	23.8	18.9	69.5	48.2
Other expense (income)
Interest expense	3.9	5.2	12.2	16.1
Interest income	(0.1)	(0.1)	(0.4)	(0.3)
Total other expenses	3.8	5.1	11.8	15.8
Earnings before income taxes	20.0	13.8	57.7	32.4
Income tax expense	4.9	1.6	15.0	6.5
Net income	15.1	12.2	42.7	25.9
Less: Net income attributable to noncontrolling interest	0.8	0.7	2.3	3.1
Net income attributable to SP Plus Corporation	$ 14.3	$ 11.5	$ 40.4	$ 22.8
Net income per common share
Basic (in dollars per share)	$ 0.69	$ 0.54	$ 1.92	$ 1.08
Diluted (in dollars per share)	$ 0.68	$ 0.54	$ 1.90	$ 1.07
Weighted average shares outstanding
Basic (in shares)	20,744,813	21,184,583	21,054,095	21,158,667
Diluted (in shares)	20,977,667	21,400,386	21,223,982	21,365,282
Lease and Management Type Contracts
Services revenue	$ 207.1	$ 161.6	$ 588.0	$ 431.5
Cost of services (exclusive of depreciation and amortization)	148.9	115.6	419.6	300.7
Lease Type Contracts
Services revenue	72.2	59.7	205.4	153.3
Cost of services (exclusive of depreciation and amortization)	59.0	48.0	166.9	122.8
Management Type Contracts
Services revenue	134.9	101.9	382.6	278.2
Cost of services (exclusive of depreciation and amortization)	89.9	64.1	252.7	174.3
Lease Impairment
Cost of services (exclusive of depreciation and amortization)		3.5		3.6
Reimbursed Management Type Contract Revenue
Services revenue	197.3	150.0	547.2	402.5
Cost of services (exclusive of depreciation and amortization)	$ 197.3	$ 150.0	$ 547.2	$ 402.5