Condensed Consolidated Statements of Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Parking services revenue
Lease type contracts	$ 99.5	$ 130.8
Management type contracts	94.4	92.1
Total parking services revenue	193.9	222.9
Reimbursed management type contract revenue	172.9	179.0
Total parking services revenue	366.8	401.9
Cost of parking services
Lease type contracts	94.6	125.8
Management type contracts	59.9	56.6
Total cost of parking services, gross	154.5	182.4
Reimbursed management type contract expense	172.9	179.0
Total cost of parking services	327.4	361.4
Gross profit
Lease type contracts	4.9	5.0
Management type contracts	34.5	35.5
Total gross profit	39.4	40.5
General and administrative expenses	22.3	21.2
Depreciation and amortization	4.0	6.6
Operating income	13.1	12.7
Other expenses (income)
Interest expense	2.1	2.6
Interest income	(0.1)	(0.1)
Equity in (earnings) losses from investment in unconsolidated entity	(10.1)	0.2
Total other (income) expenses	(8.1)	2.7
Earnings before income taxes	21.2	10.0
Income tax expense	5.3	3.3
Net income	15.9	6.7
Less: Net income attributable to noncontrolling interest	0.6	0.7
Net income attributable to SP Plus Corporation	$ 15.3	$ 6.0
Net income per common share
Basic (in dollars per share)	$ 0.69	$ 0.27
Diluted (in dollars per share)	$ 0.68	$ 0.27
Weighted average shares outstanding
Basic (in shares)	22,308,694	22,148,265
Diluted (in shares)	22,557,326	22,447,904