Condensed Consolidated Statements of Shareholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Outstanding Ordinary Shares [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Income [Member]	Retained Earnings [Member]
Beginning Balance, Amount at Jan. 31, 2021	$ 474,976	$ 16	$ 347,458	$ 1,219	$ 126,283
Beginning Balance, Shares at Jan. 31, 2021		35,547,440
Issuance of shares through employee equity plans, Amount	6,741	$ 0	6,741	0	0
Issuance of shares through employee equity plans, Shares		643,120
Issuance of shares through employee stock purchase plan, Amount	3,694	$ 0	3,694	0	0
Issuance of shares through employee stock purchase plan, Shares		82,783
Stock-based compensation expense	17,128	$ 0	17,128	0	0
Net unrealized losses on investments - net of tax	(427)	0	0	(427)	0
Net loss	(10,818)	0	0	0	(10,818)
Ending Balance, Amount at Apr. 30, 2021	491,294	$ 16	375,021	792	115,465
Ending Balance, Shares at Apr. 30, 2021		36,273,343
Beginning Balance, Amount at Jan. 31, 2022	$ 547,176	$ 17	447,287	0	99,872
Beginning Balance, Shares at Jan. 31, 2022	37,302,818	37,302,818
Issuance of shares through employee equity plans, Amount	$ 8,589	$ 0	8,589	0	0
Issuance of shares through employee equity plans, Shares		736,516
Issuance of shares through employee stock purchase plan, Amount	3,250	$ 0	3,250	0	0
Issuance of shares through employee stock purchase plan, Shares		43,545
Stock-based compensation expense	26,155	$ 0	26,155	0	0
Net unrealized losses on investments - net of tax	0	0	0	0	0
Net loss	(10,822)	0	0	$ 0	(10,822)
Ending Balance, Amount at Apr. 30, 2022	$ 574,348	$ 17	$ 485,281		$ 89,050
Ending Balance, Shares at Apr. 30, 2022	38,082,879	38,082,879