CONSOLIDATED BALANCE SHEETS (Parenthetical) In Thousands, except Share data (USD $)	Dec. 31, 2011	Dec. 31, 2010
Stockholders' equity
Convertible redeemable preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Convertible redeemable preferred stock, shares authorized (in shares)	5,000	5,000
Convertible redeemable preferred stock, shares issued (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	200,000	200,000
Common stock, shares issued (in shares)	70,454	70,578
Common stock, shares outstanding (in shares)	70,454	70,578