Common Stock Reserved for Issuance - Schedule of Common Stock Reserved for Issuance (Detail) - shares
|
Jun. 30, 2015 |
Dec. 31, 2014 |
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
| Total common stock reserved for future issuance |
22,126,461
|
22,154,290
|
| Outstanding Preferred Stock Warrants [Member] |
|
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
| Total common stock reserved for future issuance |
885,201
|
976,492
|
| Series A Convertible Preferred Stock [Member] |
|
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
| Total common stock reserved for future issuance |
252,817
|
252,817
|
| Series B Redeemable Convertible Preferred Stock [Member] |
|
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
| Total common stock reserved for future issuance |
1,947,354
|
1,947,354
|
| Series B-1 Redeemable Convertible Preferred Stock [Member] |
|
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
| Total common stock reserved for future issuance |
1,478,328
|
1,392,300
|
| Series C Redeemable Convertible Preferred Stock [Member] |
|
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
| Total common stock reserved for future issuance |
2,493,017
|
2,487,770
|
| Series D Redeemable Convertible Preferred Stock [Member] |
|
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
| Total common stock reserved for future issuance |
11,409,360
|
11,409,360
|
| Outstanding And Issued Stock Options [Member] |
|
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
| Total common stock reserved for future issuance |
3,294,849
|
2,138,096
|
| Shares Reserved For Future Option Grants [Member] |
|
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
| Total common stock reserved for future issuance |
365,535
|
1,550,101
|