Fair Value Measurements (Details) - Fair value, measurements, recurring - USD ($) $ in Millions | Oct. 31, 2019 | Jul. 31, 2019 |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | | |
Cash equivalents | $ 640.8 | $ 454.8 |
Short-term investments | 1,597.5 | 1,841.7 |
Long-term investments | 467.6 | 575.4 |
Prepaid expenses and other current assets | 0.4 | 1.3 |
Total assets measured at fair value | 2,706.3 | 2,873.2 |
Accrued and other liabilities | 2.2 | 3.8 |
Total liabilities measured at fair value | 2.2 | 3.8 |
Level 1 | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | | |
Cash equivalents | 617.3 | 369.1 |
Short-term investments | 0 | 0 |
Long-term investments | 0 | 0 |
Prepaid expenses and other current assets | 0 | 0 |
Total assets measured at fair value | 617.3 | 369.1 |
Accrued and other liabilities | 0 | 0 |
Total liabilities measured at fair value | 0 | 0 |
Level 2 | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | | |
Cash equivalents | 23.5 | 85.7 |
Short-term investments | 1,597.5 | 1,841.7 |
Long-term investments | 467.6 | 575.4 |
Prepaid expenses and other current assets | 0.4 | 1.3 |
Total assets measured at fair value | 2,089 | 2,504.1 |
Accrued and other liabilities | 2.2 | 3.8 |
Total liabilities measured at fair value | 2.2 | 3.8 |
Level 3 | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | | |
Cash equivalents | 0 | 0 |
Short-term investments | 0 | 0 |
Long-term investments | 0 | 0 |
Prepaid expenses and other current assets | 0 | 0 |
Total assets measured at fair value | 0 | 0 |
Accrued and other liabilities | 0 | 0 |
Total liabilities measured at fair value | 0 | 0 |
Money market funds | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | | |
Cash equivalents | 617.3 | 369.1 |
Money market funds | Level 1 | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | | |
Cash equivalents | 617.3 | 369.1 |
Money market funds | Level 2 | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | | |
Cash equivalents | 0 | 0 |
Money market funds | Level 3 | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | | |
Cash equivalents | 0 | 0 |
Commercial paper | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | | |
Cash equivalents | 4.5 | 19.3 |
Short-term investments | 15.9 | 8.9 |
Commercial paper | Level 1 | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | | |
Cash equivalents | 0 | 0 |
Short-term investments | 0 | 0 |
Commercial paper | Level 2 | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | | |
Cash equivalents | 4.5 | 19.3 |
Short-term investments | 15.9 | 8.9 |
Commercial paper | Level 3 | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | | |
Cash equivalents | 0 | 0 |
Short-term investments | 0 | 0 |
Corporate debt securities | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | | |
Short-term investments | 369.9 | 375.5 |
Long-term investments | 198.3 | 214.3 |
Corporate debt securities | Level 1 | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | | |
Short-term investments | 0 | 0 |
Long-term investments | 0 | 0 |
Corporate debt securities | Level 2 | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | | |
Short-term investments | 369.9 | 375.5 |
Long-term investments | 198.3 | 214.3 |
Corporate debt securities | Level 3 | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | | |
Short-term investments | 0 | 0 |
Long-term investments | 0 | 0 |
U.S. government and agency securities | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | | |
Cash equivalents | 15 | 54.4 |
Short-term investments | 1,188 | 1,439.8 |
Long-term investments | 269.3 | 361.1 |
U.S. government and agency securities | Level 1 | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | | |
Cash equivalents | 0 | 0 |
Short-term investments | 0 | 0 |
Long-term investments | 0 | 0 |
U.S. government and agency securities | Level 2 | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | | |
Cash equivalents | 15 | 54.4 |
Short-term investments | 1,188 | 1,439.8 |
Long-term investments | 269.3 | 361.1 |
U.S. government and agency securities | Level 3 | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | | |
Cash equivalents | 0 | 0 |
Short-term investments | 0 | 0 |
Long-term investments | 0 | 0 |
Certificates of deposit | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | | |
Cash equivalents | 4 | 12 |
Short-term investments | 23.7 | 17.5 |
Certificates of deposit | Level 1 | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | | |
Cash equivalents | 0 | 0 |
Short-term investments | 0 | 0 |
Certificates of deposit | Level 2 | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | | |
Cash equivalents | 4 | 12 |
Short-term investments | 23.7 | 17.5 |
Certificates of deposit | Level 3 | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | | |
Cash equivalents | 0 | |
Short-term investments | 0 | 0 |
Foreign currency forward contracts | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | | |
Foreign currency forward contracts assets | 0.4 | 1.3 |
Foreign currency forward contracts liabilities | 2.2 | 3.8 |
Foreign currency forward contracts | Level 1 | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | | |
Foreign currency forward contracts assets | 0 | 0 |
Foreign currency forward contracts liabilities | 0 | 0 |
Foreign currency forward contracts | Level 2 | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | | |
Foreign currency forward contracts assets | 0.4 | 1.3 |
Foreign currency forward contracts liabilities | 2.2 | 3.8 |
Foreign currency forward contracts | Level 3 | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | | |
Foreign currency forward contracts assets | 0 | 0 |
Foreign currency forward contracts liabilities | $ 0 | $ 0 |