XML 42 R30.htm IDEA: XBRL DOCUMENT v3.10.0.1
Convertible Senior Notes - Schedule of Interest Expense for the Notes (Details) - Convertible Debt - USD ($)
$ in Thousands
3 Months Ended 9 Months Ended
Oct. 31, 2018
Oct. 31, 2017
Oct. 31, 2018
Oct. 31, 2017
Debt Instrument [Line Items]        
Contractual interest expense $ 563 $ 0 $ 763 $ 0
Amortization of debt discount 2,938 0 3,971 0
Amortization of issuance costs 174 0 234 0
Total $ 3,675 $ 0 $ 4,968 $ 0