CASH EQUIVALENTS, AND SHORT-TERM INVESTMENTS (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2021	Jan. 31, 2020	Jan. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Cash and cash equivalents, cost basis	$ 663,843	$ 379,146	$ 369,975
Cash and cash equivalents, fair value	663,843	379,146
Maturities and sales of investments	120,900	59,300	$ 33,100
Bank time deposits
Debt Securities, Available-for-sale [Line Items]
Cost Basis	51,013	20,215
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	51,013	20,215
Total short-term investments
Debt Securities, Available-for-sale [Line Items]
Cost Basis	51,013	20,215
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	51,013	20,215
Cash and bank time deposits
Debt Securities, Available-for-sale [Line Items]
Cash and cash equivalents, cost basis	321,753	379,057
Cash and cash equivalents, fair value	321,753	379,057
Money market funds
Debt Securities, Available-for-sale [Line Items]
Cash and cash equivalents, cost basis	342,090	89
Cash and cash equivalents, fair value	$ 342,090	$ 89