Segment Information (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Income (Loss) from Continuing Operations before Income Taxes, Extraordinary Items, Noncontrolling Interest									$ 272.0	$ 363.5		$ 332.7
Segment Reporting Unallocated Corporate Expenses									49.8	57.4		71.4
Continued Dumping And Subsidy Offset Act Receipt Net Of Expenses	$ 6.0		$ 6.1	$ 47.7					59.6	0.0		0.0
Unallocated Portion of Pension Settlement Charges									(28.1)	(465.0)		(33.0)
Net sales to external customers:
Net sales	654.8	$ 657.4	$ 673.6	$ 684.0	$ 714.4	$ 707.4	$ 728.0	$ 722.5	2,669.8	2,872.3	$ 20.6	3,076.2
Segment EBIT:
Interest expense									(33.5)	(33.4)		(28.7)
Interest income									1.9	2.7		4.4
Income (Loss) From Continuing Operations Before Income Taxes									222.1	(189.6)		204.0
Assets employed at year-end:
Assets employed at year-end	2,758.3				2,784.1				2,758.3	2,784.1
Payments to Acquire Property, Plant, and Equipment									137.5	105.6		126.8
Depreciation and amortization:
Depreciation and amortization									131.7	130.8		137.0
Mobile Industries [Member]
Segment Reporting Information [Line Items]
Income (Loss) from Continuing Operations before Income Taxes, Extraordinary Items, Noncontrolling Interest									108.8	173.3		65.6
Net sales to external customers:
Net sales									1,446.4	1,558.3		1,685.4
Assets employed at year-end:
Assets employed at year-end	1,159.5				1,240.1				1,159.5	1,240.1
Payments to Acquire Property, Plant, and Equipment									88.4	47.5		55.7
Depreciation and amortization:
Depreciation and amortization									64.9	61.4		65.7
Process Industries [Member]
Segment Reporting Information [Line Items]
Income (Loss) from Continuing Operations before Income Taxes, Extraordinary Items, Noncontrolling Interest									163.2	190.2		267.1
Net sales to external customers:
Net sales									1,223.4	1,314.0		1,390.8
Assets employed at year-end:
Assets employed at year-end	1,320.5				1,226.9				1,320.5	1,226.9
Payments to Acquire Property, Plant, and Equipment									48.4	57.5		70.1
Depreciation and amortization:
Depreciation and amortization									65.6	68.1		68.8
Corporate [Member]
Segment Reporting Information [Line Items]
Continued Dumping And Subsidy Offset Act Receipt Net Of Expenses									59.6	0.0		0.0
Assets employed at year-end:
Assets employed at year-end	$ 278.3				$ 317.1				278.3	317.1
Payments to Acquire Property, Plant, and Equipment									0.7	0.6		1.0
Depreciation and amortization:
Depreciation and amortization									$ 1.2	$ 1.3		$ 2.5