Consolidated Balance Sheets (Parentheticals) (USD $)	Dec. 31, 2012	Dec. 31, 2011
Common stock par value (in Dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	95,733,677	94,497,526
Treasury stock, shares	10,115,951	2,803,987