XML 70 R51.htm IDEA: XBRL DOCUMENT v3.8.0.1
Summary of Significant Accounting Policies - Reconciliation of Numerators and Denominators of EPS Calculation (Detail) - USD ($)
$ / shares in Units, shares in Thousands, $ in Thousands
 3 Months Ended 12 Months Ended
Mar. 31, 2018
Dec. 31, 2017
Sep. 30, 2017
Jun. 30, 2017
Mar. 31, 2017
Dec. 31, 2016
Sep. 30, 2016
Jun. 30, 2016
Mar. 31, 2018
Mar. 31, 2017
Mar. 31, 2016
Numerator:                      
Net loss $ (5,995) $ (4,248) $ (7,281) $ (15,252) $ (6,925) $ (2,768) $ (7,325) $ (10,355) $ (32,776) $ (27,373) $ (23,139)
Denominator:                      
Weighted-average shares of common stock outstanding (in shares)                 19,621 14,231 13,295
Weighted-average shares subject to repurchase (in shares)                 (654) (427) (117)
Shares used in per-share calculation ― basic (in shares)                 18,967 13,804 13,178
Shares used in per-share calculation ― diluted (in shares)                 18,967 13,804 13,178
Net loss per share ― basic (in dollars per share) $ (0.30) $ (0.21) $ (0.38) $ (0.91) $ (0.50) $ (0.20) $ (0.53) $ (0.76) $ (1.73) $ (1.98) $ (1.76)
Net loss per share ― diluted (in dollars per share) $ (0.30) $ (0.21) $ (0.38) $ (0.91) $ (0.50) $ (0.20) $ (0.53) $ (0.76) $ (1.73) $ (1.98) $ (1.76)