XML 19 R71.htm IDEA: XBRL DOCUMENT v3.20.1
Employee Savings Plan - Additional Information (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Retirement Benefits [Abstract]    
Defined contribution plan, Employer discretionary contribution amount $ 0.7 $ 0.5