Income Taxes (Details) - USD ($)
$ in Thousands
3 Months Ended
Apr. 30, 2019
Apr. 30, 2018
Jan. 31, 2019
Income Tax Disclosure [Abstract]      
Income tax expense $ 245 $ 104  
Unrecognized tax benefits 7,100   $ 6,600
Unrecognized tax benefits that would affect effective tax rate if recognized $ 1,000