Condensed Consolidated Statements of Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Parking services revenue
Lease contracts	$ 140.9	$ 136.1	$ 422.6	$ 410.3
Management contracts	86.7	84.1	262.8	262.0
Total parking services revenue	227.6	220.2	685.4	672.3
Reimbursed management contract revenue	165.1	177.0	512.7	501.8
Total parking services revenue	392.7	397.2	1,198.1	1,174.1
Cost of parking services
Lease contracts	131.0	125.8	387.0	380.4
Management contracts	50.7	50.5	154.5	162.6
Total cost of parking services, gross	181.7	176.3	541.5	543.0
Reimbursed management contract expense	165.1	177.0	512.7	501.8
Total cost of parking services	346.8	353.3	1,054.2	1,044.8
Gross profit
Lease contracts	9.9	10.3	35.6	29.9
Management contracts	36.0	33.6	108.3	99.4
Total gross profit	45.9	43.9	143.9	129.3
General and administrative expenses	19.6	20.3	63.3	67.0
Depreciation and amortization	4.9	7.8	16.3	26.8
Operating income	21.4	15.8	64.3	35.5
Other expenses (income)
Interest expense	2.2	2.7	7.1	8.1
Interest income	(0.2)	(0.1)	(0.5)	(0.4)
Gain on sale of business	0.0	0.0	(0.1)	0.0
Equity in losses from investment in unconsolidated entity	0.1	0.4	0.5	1.2
Total other expenses (income)	2.1	3.0	7.0	8.9
Earnings before income taxes	19.3	12.8	57.3	26.6
Income tax expense	7.3	5.1	21.3	10.9
Net income	12.0	7.7	36.0	15.7
Less: Net income attributable to noncontrolling interest	0.8	0.7	2.6	2.2
Net income attributable to SP Plus Corporation	$ 11.2	$ 7.0	$ 33.4	$ 13.5
Net income per common share
Basic (in dollars per share)	$ 0.51	$ 0.31	$ 1.51	$ 0.60
Diluted (in dollars per share)	$ 0.50	$ 0.31	$ 1.48	$ 0.60
Weighted average shares outstanding
Basic (in shares)	22,203,023	22,208,139	22,186,556	22,293,776
Diluted (in shares)	22,523,036	22,497,111	22,501,378	22,571,933