Summary of Significant Accounting Policies - Narrative (Details) - USD ($) |
Apr. 30, 2019 |
Mar. 31, 2019 |
Feb. 01, 2019 |
Jan. 31, 2019 |
|---|---|---|---|---|
| Accounting Policies [Abstract] | ||||
| Equity investments in privately-held companies | $ 15,500,000 | $ 0 | ||
| New Accounting Pronouncements or Change in Accounting Principle [Line Items] | ||||
| Operating lease right-of-use assets | $ 143,361,000 | |||
| Operating lease liabilities | 171,699,000 | |||
| Derecognition related to build-to-suit asset | (84,094,000) | $ (75,832,000) | ||
| Accounting Standards Update 2016-02 | ||||
| New Accounting Pronouncements or Change in Accounting Principle [Line Items] | ||||
| Operating lease right-of-use assets | $ 93,900,000 | |||
| Operating lease liabilities | 121,800,000 | |||
| Deferred rent | 26,600,000 | |||
| Israel Leased Property | Other Capitalized Property Plant and Equipment | Accounting Standards Update 2016-02 | ||||
| New Accounting Pronouncements or Change in Accounting Principle [Line Items] | ||||
| Derecognition related to build-to-suit asset | $ 2,500,000 | |||
| Derecognition related to build-to-suit liability | $ 2,500,000 |