CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Thousands, except Per Share data, unless otherwise specified	6 Months Ended	12 Months Ended
	Jun. 30, 2011	Dec. 31, 2010
Accounts receivable, allowances (in dollars)	$ 2,265	2,445
Series A 3% Redeemable Convertible Preferred Stock, par value (in dollars per share)	$ 0.001	0.001
Series A 3% Redeemable Convertible Preferred Stock, Authorized shares	100	100
Series A 3% Redeemable Convertible Preferred Stock, Issued shares	75	75
Series A 3% Redeemable Convertible Preferred Stock, outstanding shares	75	75
Series A 3% Redeemable Convertible Preferred Stock, Redemption value (in dollars)	$ 87,089	87,089
Preferred Stock, par value (in dollars per share)	$ 0.001	0.001
Preferred Stock, Authorized shares	4,900	4,900
Preferred Stock, Issued shares	0	0
Preferred Stock, outstanding shares	0	0
Common Stock, par value (in dollars per share)	$ 0.001	0.001
Common Stock, Authorized shares	75,000	75,000
Common Stock, Issued shares	31,424	31,102
Common Stock, outstanding shares	27,446	27,112
Treasury stock, shares	3,978	3,990
Series A Preferred Stock
Series A 3% Redeemable Convertible Preferred Stock, interest rate (as a percent)	3.00%	3.00%