Comprehensive Income (Loss) - Components of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
AOCI Attributable to Parent, Net of Tax
Beginning Balance	$ 183.1
Other comprehensive loss before reclassification	0.1	$ (3.2)
Amounts reclassified from accumulated other comprehensive loss	0.8	0.3
Ending Balance	198.3
Foreign Currency Translation Adjustments
AOCI Attributable to Parent, Net of Tax
Beginning Balance	(2.2)	(2.3)
Other comprehensive loss before reclassification	0.1	(0.3)
Ending Balance	(2.1)	(2.6)
Change in Fair Value of Interest Rate Collars
AOCI Attributable to Parent, Net of Tax
Beginning Balance	(2.2)	(0.4)
Other comprehensive loss before reclassification		(2.9)
Amounts reclassified from accumulated other comprehensive loss	0.8	0.3
Ending Balance	(1.4)	(3.0)
Accumulated Other Comprehensive Loss
AOCI Attributable to Parent, Net of Tax
Beginning Balance	(4.4)	(2.7)
Ending Balance	$ (3.5)	$ (5.6)