Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	Jun. 30, 2012	Dec. 31, 2011
Condensed Consolidated Balance Sheets
Preferred stock, authorized shares	25,000,000	25,000,000
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, issued shares	0	0
Common stock, authorized shares	200,000,000	200,000,000
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares issued	76,821,553	76,821,553
Treasury stock, shares	649,457	938,666