Intangible Assets Amortization (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Oct. 31, 2020	Jan. 31, 2020
Finite-Lived Intangible Assets
Gross Fair Value	$ 345,529	$ 341,610
Accumulated Amortization	(146,319)	(103,195)
Total	199,210	238,415
Developed technology
Finite-Lived Intangible Assets
Gross Fair Value	256,449	252,530
Accumulated Amortization	(117,212)	(87,112)
Total	$ 139,237	$ 165,418
Acquired intangible assets, remaining useful life	62 months	68 months
Customer relationships
Finite-Lived Intangible Assets
Gross Fair Value	$ 81,810	$ 81,810
Accumulated Amortization	(24,403)	(12,403)
Total	$ 57,407	$ 69,407
Acquired intangible assets, remaining useful life	44 months	53 months
Other acquired intangible assets
Finite-Lived Intangible Assets
Gross Fair Value	$ 7,270	$ 7,270
Accumulated Amortization	(4,704)	(3,680)
Total	$ 2,566	$ 3,590
Acquired intangible assets, remaining useful life	23 months	32 months