Income Taxes - Deferred Tax Assets (Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Deferred tax assets:
Operating losses	$ 69.3	$ 63.9
Interest expense carryforward	121.4	93.5
Restructuring charges	3.6	2.3
Bad debts	5.3	4.9
Accrued expenses	15.4	9.3
Capital loss and credit carryforwards	15.7	14.0
Pension and postretirement benefits	30.9	70.8
ASC 842 - Lease liability	4.9	18.3
Other	11.4	9.2
Total deferred tax assets	277.9	286.2
Valuation allowance	(39.4)	(36.6)
Net deferred tax assets	238.5	249.6
Deferred tax liabilities:
Intangibles	(1,417.5)	(1,319.6)
Foreign exchange	0.0	(6.3)
Fixed assets	(5.1)	0.0
ASC 842 - ROU asset	(3.2)	(16.2)
Other	(1.4)	0.0
Total deferred tax liabilities	(1,427.2)	(1,342.1)
Net deferred tax (liabilities) assets	$ (1,188.7)	$ (1,092.5)