CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Dec. 31, 2012	Dec. 31, 2011
CONSOLIDATED BALANCE SHEETS
Preferred stock, Par value per share	$ 1.00	$ 1.00
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, Par value per share	$ 0.01	$ 0.01
Common stock, shares authorized	140,000,000	140,000,000
Common stock, shares issued and outstanding	79,131,299	78,127,480
Treasury stock, shares	24,145,773	17,284,287