Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 48.1	$ 35.3	$ (172.9)
Reclassification of de-designated interest rate collars	0.5	1.7	1.1
Change in fair value of interest rate collars			(2.9)
Foreign currency translation gain (loss)	0.5	(0.1)	0.1
Comprehensive income (loss)	49.1	36.9	(174.6)
Less: Comprehensive income (loss) attributable to noncontrolling interest	2.9	3.6	(0.1)
Comprehensive income (loss) attributable to SP Plus Corporation	$ 46.2	$ 33.3	$ (174.5)