XML 27 R37.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Share-based Compensation - Summary of RSU Activity (Details)
12 Months Ended
Dec. 31, 2018
$ / shares
shares
Restricted Stock Awards, Number of Shares  
Restricted stock units outstanding, beginning of period | shares 842
Vested and released | shares (842)
Restricted Stock Awards, Weighted Average Grant Date Fair Value  
Restricted stock units outstanding, beginning of period | $ / shares $ 142.92
Vested and released | $ / shares $ 142.92