Financial Statements Details - Cash, Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands	Jun. 30, 2019		Dec. 31, 2018	Jun. 30, 2018		Dec. 31, 2017
Balance Sheet Components [Abstract]
Cash and cash equivalents	$ 944,414		$ 649,950	$ 711,157
Restricted cash included in other assets	4,222			5,512
Total cash, cash equivalents and restricted cash	948,636	[1]	$ 654,164	716,669	[1]	$ 864,697
Restricted cash, pledged as collateral	$ 4,000			4,000
Restricted cash, letter of credit				$ 1,100

[1] See Note 4 of the accompanying notes for a reconciliation of the ending balance of cash, cash equivalents and restricted cash as shown in this condensed consolidated statements of cash flows.