Selected Quarterly Financial Data (unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands |
3 Months Ended | 12 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Dec. 31, 2015 |
Sep. 30, 2015 |
Jun. 30, 2015 |
Mar. 31, 2015 |
Dec. 31, 2014 |
Sep. 30, 2014 |
Jun. 30, 2014 |
Mar. 31, 2014 |
Dec. 31, 2015 |
Dec. 31, 2014 |
Dec. 31, 2013 |
|
| Quarterly Financial Information Disclosure [Abstract] | |||||||||||
| Total revenue | $ 21,315 | $ 19,539 | $ 18,510 | $ 15,951 | $ 14,487 | $ 12,209 | $ 10,533 | $ 8,376 | $ 75,315 | $ 45,605 | $ 12,973 |
| Gross profit | 11,660 | 10,852 | 10,256 | 8,779 | 7,870 | 5,054 | 3,116 | 1,793 | 41,547 | 17,833 | (4,331) |
| Net loss | $ (19,058) | $ (20,007) | $ (21,212) | $ (19,643) | $ (19,684) | $ (20,199) | $ (21,776) | $ (24,281) | $ (79,920) | $ (85,940) | $ (62,182) |
| Net loss per share, basic and diluted | $ (0.20) | $ (0.21) | $ (0.23) | $ (0.21) | $ (0.22) | $ (0.23) | $ (0.24) | $ (0.90) | $ (0.85) | $ (1.16) | $ (6.28) |