v3.20.1
Intangible assets and goodwill - Narrative (Details) - USD ($)
$ in Thousands
12 Months Ended
Jan. 31, 2020
Jan. 31, 2019
Jan. 31, 2018
Finite-Lived Intangible Assets [Line Items]      
Fair value $ 7,659 $ 1,195  
Capitalized software development costs 24,100 9,300 $ 8,100
Software development costs incurred and expensed 23,800 13,700 12,200
Amortization expense $ 46,500 $ 14,700 $ 13,200
Acquired HSA Intangible Assets      
Finite-Lived Intangible Assets [Line Items]      
Weighted-average remaining amortization period (years) 15 years    
WageWorks, Inc.      
Finite-Lived Intangible Assets [Line Items]      
Total acquired intangible assets $ 711,500    
Goodwill $ 1,330,000