Convertible Senior Notes, Net - Note Hedges, Warrants and Capped Calls (Details) $ / shares in Units, shares in Thousands, $ in Thousands	1 Months Ended		12 Months Ended
	Jun. 30, 2020 USD ($) shares	Sep. 30, 2019 USD ($) shares	Jan. 31, 2022 USD ($) tradingDay $ / shares shares	Jan. 31, 2021 USD ($) shares	Jan. 31, 2020 USD ($) shares
Debt Instrument [Line Items]
Proceeds from hedges related to convertible senior notes | $			$ 2	$ 195,046	$ 405,851
Payments for repurchase of warrants | $			$ 0	$ 175,399	$ 358,622
Antidilutive securities excluded from computation of earnings per share (in shares) | shares			27,573	25,156	28,292
Payment for capped calls | $			$ 0	$ 133,975	$ 74,094
2023 Notes
Debt Instrument [Line Items]
Shares issuable under warrants granted (in shares) | shares	1,400	4,600
Number of shares available for purchase | shares			400
Number of warrants outstanding (in shares) | shares			1,000
Limitation on sale of common stock, sale price threshold, number of trading days | tradingDay			80
Per share value, shares issuable under warrants granted (in dollars per share) | $ / shares			$ 68.06
Proceeds from issuance of warrants related to convertible senior notes | $			$ 52,400
Payments for repurchase of warrants | $	$ 175,400	$ 358,600
2025 Notes
Debt Instrument [Line Items]
Initial cap price (in dollars per share) | $ / shares			$ 255.88
Payment for capped calls | $			$ 74,100
2026 Notes
Debt Instrument [Line Items]
Initial cap price (in dollars per share) | $ / shares			$ 360.14
Payment for capped calls | $			$ 134,000
Senior Notes | 2023 Notes
Debt Instrument [Line Items]
Shares issuable under warrants granted (in shares) | shares	1,400	4,600	7,100
Conversion price (in dollars per share) | $ / shares			$ 48.36
Aggregate amount paid for cost of Note Hedge | $			$ 80,000
Proceeds from hedges related to convertible senior notes | $	$ 195,000	$ 405,900
Hedge exercised, underlying debt instrument amount | $			$ 23,000
Number of warrants outstanding (in shares) | shares			7,100
Limitation on sale of common stock, sale price threshold, number of trading days | tradingDay			20
Senior Notes | 2023 Notes | Class A Common Stock
Debt Instrument [Line Items]
Hedge exercised, number of shares received | shares			400
Senior Notes | 2025 Notes
Debt Instrument [Line Items]
Conversion price (in dollars per share) | $ / shares			$ 188.71
Senior Notes | 2026 Notes
Debt Instrument [Line Items]
Conversion price (in dollars per share) | $ / shares			$ 238.60
Convertible debt securities
Debt Instrument [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares) | shares			356	832	2,494
Convertible debt securities | 2025 Notes
Debt Instrument [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares) | shares			5,600
Convertible debt securities | 2026 Notes
Debt Instrument [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares) | shares			4,800