Consolidated Statements of Income (Loss) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Services revenue	$ 1,177.2	$ 1,086.9	$ 1,663.7
Cost of services (exclusive of depreciation and amortization)	997.4	1,056.5	1,435.6
General and administrative expenses	88.2	85.4	109.0
Depreciation and amortization	25.1	29.3	29.4
Impairment of goodwill and intangible assets	0.0	135.3	0.0
Operating income (loss)	66.5	(219.6)	89.7
Other expense (income)
Interest expense	21.2	21.5	18.9
Interest income	(0.4)	(0.5)	(0.3)
Other income	(0.1)	(0.2)	0.0
Total other expenses	20.7	20.8	18.6
Earnings (loss) before income taxes	45.8	(240.4)	71.1
Income tax expense (benefit)	10.5	(67.5)	19.4
Net income (loss)	35.3	(172.9)	51.7
Less: Net income (loss) attributable to noncontrolling interest	3.6	(0.1)	2.9
Net income (loss) attributable to SP Plus Corporation	$ 31.7	$ (172.8)	$ 48.8
Net income (loss) per common share
Basic (in dollars per share)	$ 1.50	$ (8.21)	$ 2.21
Diluted (in dollars per share)	$ 1.48	$ (8.21)	$ 2.20
Weighted average shares outstanding
Basic (in shares)	21,166,323	21,056,061	22,080,025
Diluted (in shares)	21,379,983	21,056,061	22,208,032
Lease and Management Type Contracts
Services revenue	$ 601.5	$ 549.0	$ 934.9
Cost of services (exclusive of depreciation and amortization)	421.7	518.6	706.8
Lease Type Contracts
Services revenue	215.6	189.4	408.9
Cost of services (exclusive of depreciation and amortization)	170.6	195.0	366.9
Management Type Contracts
Services revenue	385.9	359.6	526.0
Cost of services (exclusive of depreciation and amortization)	247.5	226.5	339.9
Lease Impairment
Cost of services (exclusive of depreciation and amortization)	3.6	97.1	0.0
Reimbursed Management Type Contract Revenue
Services revenue	575.7	537.9	728.8
Cost of services (exclusive of depreciation and amortization)	$ 575.7	$ 537.9	$ 728.8