Consolidated Balance Sheets (Parenthetical) (USD $)	Mar. 31, 2012	Dec. 31, 2011
Consolidated Balance Sheets [Abstract]
Accounts receivable, allowance	$ 0	$ 225,000
Temporary equity, convertible perpetual preferred stock, par value	$ 0.001	$ 0.001
Temporary equity, convertible perpetual preferred stock, shares issued	790,957	806,847
Temporary equity, convertible perpetual preferred stock, shares outstanding	790,957	806,847
Temporary equity, convertible perpetual preferred stock, liquidation value	79,100,000	80,700,000
8% convertible perpetual preferred stock, par value	$ 0.001	$ 0.001
8% convertible perpetual preferred stock, shares authorized	10,000,000	10,000,000
8% convertible perpetual preferred stock, issued	2,314,043	2,318,153
8% convertible perpetual preferred stock, outstanding	2,314,043	2,318,153
8% convertible perpetual preferred stock, liquidation value, discount	$ 231,400,000	$ 231,800,000
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	100,000,000	100,000,000
Common stock, issued	52,127,262	52,034,547
Common stock, outstanding	52,051,422	51,958,707