Revenue Recognition (Details) - USD ($) $ / shares in Units, $ in Millions			3 Months Ended
		Jan. 01, 2018	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Effect of LIFO Inventory Liquidation on Income		$ 5.0
Contract with Customer, Asset, Net, Current		55.6	$ 57.5		$ 0.0
Inventory, Net		167.2	176.8		207.9
Total current assets		671.5	682.3		656.6
Deferred tax assets, net		68.7	63.7		72.0
Assets		1,396.8	1,405.4		1,385.2
Other Accrued Liabilities, Current		42.0	35.6		40.5
Total current liabilities		174.6	184.5		173.1
Total liabilities		640.4	651.8		638.9
Retained earnings		95.6	111.7		85.5
Total stockholders' equity		756.4	753.6		746.3
Total		1,396.8	1,405.4		1,385.2
Net sales			388.0	$ 355.3
Cost of Goods Sold	[1]		316.7	262.7
Operating Income (Loss)			37.1	59.3
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest			31.6	54.5
Income tax provision			(5.9)	(18.5)
Net income			$ 25.7	$ 36.0
Earnings Per Share, Basic			$ 1.54	$ 2.07
Earnings Per Share, Diluted			$ 1.51	$ 2.04
Comprehensive income			$ 17.4	$ 37.3
Increase (Decrease) in Contract Receivables, Net			(1.9)	0.0
Increase (Decrease) in Inventories			(9.6)	(1.9)
Increase (Decrease) in Other Accrued Liabilities			(7.3)	(11.4)
Net cash provided by operating activities	[2]		26.1	$ 4.1
Difference between Revenue Guidance in Effect before and after Topic 606 | Accounting Standards Update 2014-09
Contract with Customer, Asset, Net, Current		55.6	(57.5)
Inventory, Net		(40.7)	36.1
Total current assets		14.9	(21.4)
Deferred tax assets, net		(3.3)	3.3
Assets		11.6	(18.1)
Other Accrued Liabilities, Current		1.5	(3.5)
Total current liabilities		1.5	(3.5)
Total liabilities		1.5	(3.5)
Retained earnings		10.1	(14.6)
Total stockholders' equity		10.1	(14.6)
Total		$ 11.6	(18.1)
Net sales			(1.7)
Cost of Goods Sold			4.2
Operating Income (Loss)			(5.9)
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest			(5.9)
Income tax provision			1.4
Net income			$ (4.5)
Earnings Per Share, Basic			$ (0.27)
Earnings Per Share, Diluted			$ (0.26)
Comprehensive income			$ (4.5)
Increase (Decrease) in Contract Receivables, Net			1.9
Increase (Decrease) in Inventories			4.6
Increase (Decrease) in Other Accrued Liabilities			(2.0)
Net cash provided by operating activities			0.0
Calculated under Revenue Guidance in Effect before Topic 606
Contract with Customer, Asset, Net, Current			0.0		0.0
Inventory, Net			212.9		207.9
Total current assets			660.9		656.6
Deferred tax assets, net			67.0		72.0
Assets			1,387.3		1,385.2
Other Accrued Liabilities, Current			32.1		40.5
Total current liabilities			181.0		173.1
Total liabilities			648.3		638.9
Retained earnings			97.1		85.5
Total stockholders' equity			739.0		746.3
Total			1,387.3		$ 1,385.2
Net sales			386.3
Cost of Goods Sold			320.9
Operating Income (Loss)			31.2
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest			25.7
Income tax provision			(4.5)
Net income			$ 21.2
Earnings Per Share, Basic			$ 1.27
Earnings Per Share, Diluted			$ 1.25
Comprehensive income			$ 12.9
Increase (Decrease) in Contract Receivables, Net			0.0
Increase (Decrease) in Inventories			(5.0)
Increase (Decrease) in Other Accrued Liabilities			(9.3)
Net cash provided by operating activities			$ 26.1

[1] See Note 4 for discussion of our adoption of ASU 2017-12 (as defined in Note 1) and the related reclassification of amounts previously presented in the Statements of Consolidated Income within Unrealized (gain) loss on derivative instruments and now included within Cost of products sold, excluding depreciation and amortization and other items.

[2] See Note 8 for adjustments made to arrive at our Consolidated Balance Sheet as of January 1, 2018 upon adopting ASC 606 (as defined in Note 1).