Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Allowance for doubtful accounts	$ 154	$ 97
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	10,000,000	0
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	24,803,640	9,706,270
Common stock, shares outstanding	24,803,640	9,706,270
Redeemable Convertible Preferred Stock
Redeemable stock, par value	$ 0.001	$ 0.001
Redeemable stock, shares authorized	0	427,985
Redeemable stock, shares issued	0	427,985
Redeemable stock, shares outstanding	0	427,985
Redeemable Common Stock
Redeemable stock, par value	$ 0.001	$ 0.001
Redeemable stock, shares issued	0	3,189,648
Redeemable stock, shares outstanding	0	3,189,648