XML 52 R41.htm IDEA: XBRL DOCUMENT v3.19.1
Stock-Based Compensation - Additional Information (Details) - Employee Stock Option
$ in Millions
3 Months Ended
Mar. 31, 2019
USD ($)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]  
Unrecognized compensation expense $ 3.4
Weighted-average period expected to be recognized 3 years 2 months 12 days