Net Income (Loss) per Common Share (Tables)

12 Months Ended

Dec. 31, 2022

Earnings Per Share [Abstract]

Schedule of Basic and Diluted Net Income (Loss) per Common Share and Reconciliation of Weighted Average Shares

Basic and diluted net income (loss) per common share and a reconciliation of the weighted average basic common shares outstanding to the weighted average diluted common shares outstanding during the years ending December 31, 2022, 2021 and 2020 was as follows:

	Year Ended December 31,
(millions, except share and per share data)	2022		2021		2020
Net income (loss) attributable to SP Plus Corporation	$	45.2	$	31.7	$	(172.8	)
Basic weighted average common shares outstanding		20,809,363		21,166,323		21,056,061
Dilutive impact of share-based awards		197,705		213,660		—
Diluted weighted average common shares outstanding		21,007,068		21,379,983		21,056,061
Net income (loss) per common share
Basic	$	2.17	$	1.50	$	(8.21	)
Diluted	$	2.15	$	1.48	$	(8.21	)