Leases - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2020	Jan. 31, 2019	Jan. 31, 2018
Leases [Abstract]
Operating lease liabilities, current	$ 8,640	$ 0
Operating lease liabilities, non-current	115,187	0
Operating lease right-of-use assets	$ 111,973
Operating lease, weighted average remaining lease term	10 years 1 month 6 days
Operating lease, weighted average discount rate, percentage	5.80%
Lease expense	$ 21,200
Operating lease expense	16,800
Short-term lease expense	2,200
Variable lease expense	2,200
Operating lease, payments	7,500
Right-of-use assets obtained in exchange for lease obligations	$ 110,200
Rent expense		$ 7,300	$ 6,300