Accumulated Other Comprehensive Income - Changes in AOCI (Details) $ in Millions	6 Months Ended
	Jun. 30, 2021 USD ($)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	$ 522.9
Ending Balance	629.3
Foreign currency translation
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	17.9
Other comprehensive income (loss) before reclassifications	(6.2)
Amounts reclassified from accumulated other comprehensive income (loss)	0.0
Ending Balance	11.7
Unrealized gain (loss) on interest rate swaps
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(7.2)
Other comprehensive income (loss) before reclassifications	5.1
Amounts reclassified from accumulated other comprehensive income (loss)	(2.7)
Ending Balance	(4.8)
Accumulated Other Comprehensive Income (Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	10.7
Other comprehensive income (loss) before reclassifications	(1.1)
Amounts reclassified from accumulated other comprehensive income (loss)	(2.7)
Ending Balance	$ 6.9