Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Allowance for doubtful accounts receivable	$ 0.8	$ 0.9
Common Stock, Par or Stated Value Per Share	$ 1.00	$ 1.00
Common Stock, Shares Authorized	200,000,000	200,000,000
Common Stock, Shares, Issued	153,348,542	153,348,542
Common Stock, Shares, Outstanding	0	143,169,626
Preferred Stock, Par or Stated Value Per Share	$ 1.00	$ 1.00
Preferred Stock, Shares Authorized	15,000,000	15,000,000
Preferred Stock, Shares Issued	0	0
Treasury Stock, Shares	16,525,351	8,462,949