Present and Prospective Accounting Pronouncements Effect of change related to 2014-09 (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net sales	$ 2,828.0	$ 2,733.9	$ 2,233.4
Cost of sales	2,084.0	1,998.1	1,829.1
Selling, general and administrative expense	(209.3)	(191.3)	(185.1)
Provision for income taxes	122.3	119.1	19.8
Net income	394.6	389.8	$ 149.8
Receivables, net of allowance for doubtful accounts	127.6	142.5
Inventories	273.0	259.1
Income taxes payable	21.0	4.5
Retained earnings	1,612.6	$ 1,280.1
Calculated under Revenue Guidance in Effect before Topic 606 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net sales	2,829.6
Cost of sales	2,082.0
Selling, general and administrative expense	(213.8)
Provision for income taxes	122.1
Net income	393.9
Receivables, net of allowance for doubtful accounts	146.6
Inventories	259.2
Income taxes payable	22.3
Retained earnings	1,616.3
Difference between Revenue Guidance in Effect before and after Topic 606 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net sales	1.6
Cost of sales	2.0
Selling, general and administrative expense	(4.5)
Provision for income taxes	0.2
Net income	0.7
Receivables, net of allowance for doubtful accounts	19.0
Inventories	13.8
Income taxes payable	1.3
Retained earnings	$ (3.7)