Condensed Consolidated Statements of Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Parking services revenue	$ 362.1	$ 392.7	$ 1,091.2	$ 1,198.1
Cost of parking services	317.1	346.8	955.6	1,054.2
Gross profit	45.0	45.9	135.6	143.9
General and administrative expenses	18.7	19.6	63.3	63.3
Depreciation and amortization	4.2	4.9	12.7	16.3
Operating income	22.1	21.4	59.6	64.3
Other expenses (income)
Interest expense	2.1	2.2	6.5	7.1
Interest income	(0.1)	(0.2)	(0.3)	(0.5)
Gain on sale of a business	0.0	0.0	0.0	(0.1)
Equity in losses (earnings) from investment in unconsolidated entity	0.0	0.1	(10.1)	0.5
Total other expenses (income)	2.0	2.1	(3.9)	7.0
Earnings before income taxes	20.1	19.3	63.5	57.3
Income tax expense	5.6	7.3	16.9	21.3
Net income	14.5	12.0	46.6	36.0
Less: Net income attributable to noncontrolling interest	1.0	0.8	2.5	2.6
Net income attributable to SP Plus Corporation	$ 13.5	$ 11.2	$ 44.1	$ 33.4
Net income per common share
Basic (in dollars per share)	$ 0.60	$ 0.51	$ 1.97	$ 1.51
Diluted (in dollars per share)	$ 0.60	$ 0.50	$ 1.95	$ 1.48
Weighted average shares outstanding
Basic (in shares)	22,439,884	22,203,023	22,370,789	22,186,556
Diluted (in shares)	22,626,746	22,523,036	22,607,274	22,501,378
Lease type contracts
Parking services revenue	$ 104.7	$ 140.9	$ 311.6	$ 422.6
Cost of parking services	94.2	131.0	283.2	387.0
Gross profit	10.5	9.9	28.4	35.6
Management type contracts
Parking services revenue	82.6	86.7	264.8	262.8
Cost of parking services	48.1	50.7	157.6	154.5
Gross profit	34.5	36.0	107.2	108.3
Lease and Management type contracts
Parking services revenue	187.3	227.6	576.4	685.4
Cost of parking services	142.3	181.7	440.8	541.5
Reimbursed management type contract
Parking services revenue	174.8	165.1	514.8	512.7
Cost of parking services	$ 174.8	$ 165.1	$ 514.8	$ 512.7