Consolidated Balance Sheets (Parenthetical) (USD $)	Mar. 31, 2014	Dec. 31, 2013
Statement of Financial Position [Abstract]
Common stock, par value	$ 2.50	$ 2.50
Common stock, shares authorized	600,000,000	600,000,000
Common stock, shares issued	217,900,000	217,800,000
Treasury stock, shares	29,100,000	25,200,000