Net Income per Common Share (Tables)

9 Months Ended

Sep. 30, 2018

Earnings Per Share [Abstract]

Schedule of Reconciliation of Weighted Average Shares

A reconciliation of the weighted average basic common shares outstanding to the weighted average diluted common shares outstanding is as follows:

	Three Months Ended				Nine Months Ended
(millions, except share and per share data) (unaudited)	September 30, 2018		September 30, 2017		September 30, 2018		September 30, 2017
Net income attributable to SP Plus Corporation	$	13.5	$	11.2	$	44.1	$	33.4
Basic weighted average common shares outstanding	22,439,884		22,203,023		22,370,789		22,186,556
Dilutive impact of share-based awards	186,862		320,013		236,485		314,822
Diluted weighted average common shares outstanding	22,626,746		22,523,036		22,607,274		22,501,378
Net income per common share
Basic	$	0.60	$	0.51	$	1.97	$	1.51
Diluted	$	0.60	$	0.50	$	1.95	$	1.48