CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Thousands, except Per Share data	Jun. 30, 2011	Dec. 31, 2010
Common stock
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, authorized	200,000	200,000
Common stock, outstanding	75,365	70,950
Class A common stock
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, authorized	30,000	30,000
Common stock, outstanding	9,402	9,402