Stockholders' Equity - Schedule Of Common Stock Shares Reserved For Future Issuance (Details) - shares	Mar. 31, 2018	Dec. 31, 2017
Class Of Stock [Line Items]
Total number of shares reserved for future issuance	9,030,013	7,725,133
Common stock warrants issued and outstanding
Class Of Stock [Line Items]
Total number of shares reserved for future issuance	4,857	4,857
Options Issued and Outstanding
Class Of Stock [Line Items]
Total number of shares reserved for future issuance	2,695,913	2,601,181
Unvested restricted stock units
Class Of Stock [Line Items]
Total number of shares reserved for future issuance	581,127	468,426
Shares Available for Grant Under Future Stock Plans
Class Of Stock [Line Items]
Total number of shares reserved for future issuance	5,748,116	4,650,669