Summary Stockholders' Equity (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2015 USD ($)
Balance at the beginning	$ 71,354
Balance at the ending	109,436
Common Stock
Balance at the beginning	43
Equity issued on note conversion	6
Balance at the ending	49
Additional Paid-in Capital
Balance at the beginning	230,122
Share-based compensation	3,152
Issuance of ESPP shares	324
Exercise of stock options	743
Equity issued on note conversion	26,013
Exercise of warrants	652
Balance at the ending	$ 261,006