Accumulated Other Comprehensive Income (Loss) - Components (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at beginning of period	$ 668.9	$ 768.7	$ 674.8
Balance at end of period	590.3	668.9	768.7
Cumulative Translation Adjustments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at beginning of period	(106.7)	(111.8)	(94.5)
Other comprehensive income (loss)	(2.3)	5.1	(17.3)
Balance at end of period	(109.0)	(106.7)	(111.8)
Pension and Other Postretirement Benefit Plans, Net
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at beginning of period	(56.3)	(39.4)	(45.0)
Other comprehensive income (loss)	(18.3)	(19.0)	2.5
Amounts reclassified from AOCI to net income	2.7	2.1	(3.1)
Balance at end of period	(71.9)	(56.3)	(39.4)
Accumulated Gain Loss Net Cash Flow Hedge Parent
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at beginning of period	0.6	8.9	(6.1)
Other comprehensive income (loss)	(9.0)	(0.7)	9.3
Amounts reclassified from AOCI to net income	3.2	(7.6)	(5.7)
Balance at end of period	(5.2)	0.6	8.9
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at beginning of period	(162.4)	(142.3)	(145.6)
Other comprehensive income (loss)	(29.6)	(14.6)	(5.5)
Amounts reclassified from AOCI to net income	5.9	(5.5)	(8.8)
Balance at end of period	$ (186.1)	$ (162.4)	$ (142.3)