Consolidated Statements of Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Services revenue	$ 1,663.7	$ 1,468.4	$ 1,590.5
Cost of services	1,435.6	1,284.4	1,405.2
Gross profit	228.1	184.0	185.3
General and administrative expenses	109.0	91.0	82.9
Depreciation and amortization	29.4	17.9	21.0
Operating income	89.7	75.1	81.4
Other expense (income)
Interest expense	18.9	9.6	9.2
Interest income	(0.3)	(0.4)	(0.6)
Gain on sale of a business	0.0	0.0	(0.1)
Equity in (earnings) losses from investment in unconsolidated entity	0.0	(10.1)	0.7
Total other expenses (income)	18.6	(0.9)	9.2
Earnings before income taxes	71.1	76.0	72.2
Income tax expense	19.4	19.6	27.7
Net income	51.7	56.4	44.5
Less: Net income attributable to noncontrolling interest	2.9	3.2	3.3
Net income attributable to SP Plus Corporation	$ 48.8	$ 53.2	$ 41.2
Net income per common share
Basic (in dollars per share)	$ 2.21	$ 2.38	$ 1.86
Diluted (in dollars per share)	$ 2.20	$ 2.35	$ 1.83
Weighted average shares outstanding
Basic (in shares)	22,080,025	22,394,542	22,195,350
Diluted (in shares)	22,208,032	22,607,223	22,508,288
Lease type contracts
Services revenue	$ 408.9	$ 413.9	$ 563.1
Cost of services	366.9	377.6	518.4
Gross profit	42.0	36.3	44.7
Management type contracts
Services revenue	526.0	361.5	348.2
Cost of services	339.9	213.8	207.6
Gross profit	186.1	147.7	140.6
Lease And Management Type Contracts
Services revenue	934.9	775.4	911.3
Cost of services	706.8	591.4	726.0
Reimbursed management type contract revenue
Services revenue	728.8	693.0	679.2
Cost of services	$ 728.8	$ 693.0	$ 679.2