Segment Information - Business Information (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Net sales	$ 891.7	$ 894.6	$ 803.5	$ 923.4	$ 896.2	$ 914.0	$ 1,000.0	$ 979.7	$ 3,513.2	$ 3,789.9	$ 3,580.8
Segment EBITDA									675.4	751.5	677.9
Recognition of net actuarial losses (gains)	(21.6)	$ (11.9)	$ (8.8)		(21.1)	$ (16.9)			(18.5)	4.1	(12.8)
Bargain purchase price gain									11.1	0.0	0.0
Depreciation and amortization									(167.1)	(160.6)	(146.0)
Interest expense, net									(63.9)	(67.2)	(49.6)
Income before income taxes									396.3	472.4	408.1
Assets employed at year-end:
Total assets	5,041.6				4,859.9				5,041.6	4,859.9
Capital expenditures:
Payments to acquire property, plant, and equipment									121.6	140.6	112.6
Depreciation and amortization:
Depreciation and amortization									167.1	160.6	146.0
Mobile Industries
Segment Reporting Information [Line Items]
Net sales									1,671.6	1,893.9	1,903.7
Segment EBITDA									232.5	284.9	272.2
Depreciation and amortization									(79.7)	(73.6)	(73.5)
Assets employed at year-end:
Total assets	2,082.2				2,109.9				2,082.2	2,109.9
Capital expenditures:
Payments to acquire property, plant, and equipment									70.5	74.2	48.3
Depreciation and amortization:
Depreciation and amortization									79.7	73.6	73.5
Process Industries
Segment Reporting Information [Line Items]
Net sales									1,841.6	1,896.0	1,677.1
Segment EBITDA									442.9	466.6	405.7
Depreciation and amortization									(86.6)	(86.2)	(71.9)
Assets employed at year-end:
Total assets	2,482.6				2,366.7				2,482.6	2,366.7
Capital expenditures:
Payments to acquire property, plant, and equipment									50.1	65.3	63.3
Depreciation and amortization:
Depreciation and amortization									86.6	86.2	71.9
Corporate
Segment Reporting Information [Line Items]
Corporate EBITDA									(40.7)	(55.4)	(61.4)
Depreciation and amortization									(0.8)	(0.8)	(0.6)
Assets employed at year-end:
Total assets	$ 476.8				$ 383.3				476.8	383.3
Capital expenditures:
Payments to acquire property, plant, and equipment									1.0	1.1	1.0
Depreciation and amortization:
Depreciation and amortization									$ 0.8	$ 0.8	$ 0.6