Summary Stockholders' Equity (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2015 USD ($)
Balance at the beginning	$ 71,354
Balance at the ending	102,365
Common Stock
Balance at the beginning	43
Equity issued on note conversion	5
Balance at the ending	48
Additional Paid-in Capital
Balance at the beginning	230,122
Share-based compensation	2,020
Issuance of ESPP shares	324
Exercise of stock options	685
Equity issued on note conversion	25,051
Balance at the ending	$ 258,202