CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Dec. 31, 2013	Dec. 31, 2012
Statement of Financial Position [Abstract]
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares issued	0	0
Common stock, shares authorized	150,000,000	150,000,000
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares issued	89,154,190	87,732,405
Treasury stock, shares	7,958,510	5,005,518