CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Statement Of Financial Position [Abstract]
Accounts receivable, allowances	$ 2.1	$ 1.0
Preferred Stock, par value	$ 1.00	$ 1.00
Preferred Stock, Authorized	2,500,000	2,500,000
Preferred Stock, issued	0	0
Common Stock, par value	$ 1.00	$ 1.00
Common Stock, Authorized	300,000,000	300,000,000
Common Stock, shares issued	292,855,100	292,855,100
Common stock in treasury, shares	38,892,165	32,947,012