CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Statement of Financial Position [Abstract]
Accounts receivable, allowances (in dollars)	$ 1,255	$ 1,565
Interest rate (as a percent)	3.00%	3.00%
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	100,000	100,000
Series A 3% Redeemable Convertible Preferred Stock, Issued shares	75,000	75,000
Series A 3% Redeemable Convertible Preferred Stock, outstanding shares	75,000	75,000
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	4,900,000	4,900,000
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	75,000,000	75,000,000
Common stock, Issued shares	32,385,000	31,949,000
Common stock, Outstanding shares	28,466,000	27,977,000
Treasury stock, shares	3,919,000	3,942,000