SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2020	Jan. 31, 2019	Jan. 31, 2018
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	$ 244,514	$ 165,416	$ 155,488
ASC 606 Transition Adjustment		66,617
Charges to Cost and Expenses	478,996	432,755	337,298
Deductions	489,382	420,274	327,370
Balance at End of Period	234,128	244,514	165,416
Allowance for doubtful accounts
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	924	2,093	1,192
Charges to Cost and Expenses	(72)	(140)	854
Deductions	142	1,029	(47)
Balance at End of Period	710	924	2,093
Reserve for returns
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	62,278	61,179	59,802
Charges to Cost and Expenses	56,440	57,777	32,710
Deductions	72,229	56,678	31,333
Balance at End of Period	46,489	62,278	61,179
Reserve for sales allowances
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	181,312	102,144	94,494
ASC 606 Transition Adjustment		66,617
Charges to Cost and Expenses	422,628	375,118	303,734
Deductions	417,011	362,567	296,084
Balance at End of Period	$ 186,929	$ 181,312	$ 102,144