Net Income per Common Share (Tables)

3 Months Ended

Mar. 31, 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
(millions, except share and per share data) (unaudited)	March 31, 2018		March 31, 2017
Net income attributable to SP Plus Corporation	$	15.3	$	6.0
Basic weighted average common shares outstanding	22,308,694		22,148,265
Dilutive impact of share-based awards	248,632		299,639
Diluted weighted average common shares outstanding	22,557,326		22,447,904
Net income per common share
Basic	$	0.69	$	0.27
Diluted	$	0.68	$	0.27