CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Dec. 31, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Preferred stock, par or stated value per share (in dollars per share)	$ 1.00	$ 1.00
Preferred stock, shares authorized	250,000	250,000
Preferred stock, shares issued	0	0
Common stock, par or stated value per share (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	162,800,000	162,800,000
Common stock, shares, outstanding	140,100,000	140,900,000
Treasury stock, shares	22,700,000	21,900,000