Assets and Liabilities Measured at Fair Value on a Recurring Basis - Summary of Financial Assets and Liabilities Measured at Fair Value (Detail) - USD ($) $ in Thousands		May 31, 2019		Feb. 28, 2019
Assets:
Money markets		$ 901,570	[1]	$ 398,056	[2]
Interest-bearing deposits	[2]			56,883
Available-for-sale securities, debt securities		365,797
Foreign currency derivatives		233	[3]	24	[4]
Liabilities:
Foreign currency derivatives		(173)	[5]	(245)	[6]
Total		1,523,207		1,481,461
Cash		1,140,000		943,300
Level 1
Assets:
Money markets		901,570	[1]	398,056	[2]
Interest-bearing deposits	[2]			0
Foreign currency derivatives		0	[3]	0	[4]
Liabilities:
Foreign currency derivatives		0	[5]	0	[6]
Total		901,570		398,056
Level 2
Assets:
Money markets		0	[1]	0	[2]
Interest-bearing deposits	[2]			56,883
Foreign currency derivatives	[4]			24
Liabilities:
Foreign currency derivatives	[6]			(245)
Total		621,637		1,083,405
Level 3
Assets:
Money markets		0	[1]	0	[2]
Interest-bearing deposits	[2]			0
Foreign currency derivatives		0	[3]	0	[4]
Liabilities:
Foreign currency derivatives		0	[5]	0	[6]
Total		0		0
Commercial paper
Assets:
Available-for-sale securities, debt securities		255,780	[1]	541,753	[2]
Commercial paper | Level 1
Assets:
Available-for-sale securities, debt securities		0	[1]	0	[2]
Commercial paper | Level 2
Assets:
Available-for-sale securities, debt securities		255,780	[1]	541,753	[2]
Commercial paper | Level 3
Assets:
Available-for-sale securities, debt securities		0	[1]	0	[2]
U.S. agency securities
Assets:
Available-for-sale securities, debt securities		203,135	[1]	222,298	[2]
U.S. agency securities | Level 1
Assets:
Available-for-sale securities, debt securities		0	[1]	0	[2]
U.S. agency securities | Level 2
Assets:
Available-for-sale securities, debt securities		203,135	[1]	222,298	[2]
U.S. agency securities | Level 3
Assets:
Available-for-sale securities, debt securities		0	[1]	0	[2]
Corporate securities
Assets:
Available-for-sale securities, debt securities		162,662	[1]	262,692	[2]
Corporate securities | Level 1
Assets:
Available-for-sale securities, debt securities		0	[1]	0	[2]
Corporate securities | Level 2
Assets:
Available-for-sale securities, debt securities		162,662	[1]	262,692	[2]
Corporate securities | Level 3
Assets:
Available-for-sale securities, debt securities		$ 0	[1]	$ 0	[2]

[1] Included in Cash, cash equivalents and restricted cash, Investments in debt securities, short-term or Investments in debt securities, long-term in the Company’s Consolidated Balance Sheet at May 31, 2019, in addition to $1.14 billion of cash.

[2] Included in Cash, cash equivalents and restricted cash, Investments in debt securities, short-term or Investments in debt securities, long-term in the Company’s Consolidated Balance Sheet at February 28, 2019, in addition to $943.3 million of cash.

[3] Included in Other current assets in the Company’s Consolidated Balance Sheet at May 31, 2019.

[4] Included in Other current assets in the Company’s Consolidated Balance Sheet at February 28, 2019.

[5] Included in Accounts payable and accrued expenses in the Company’s Consolidated Balance Sheet at May 31, 2019.

[6] Included in Accounts payable and accrued expenses in the Company’s Consolidated Balance Sheet at February 28, 2019.