Financial Statements Details - Cash, Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands	Jun. 30, 2018		Dec. 31, 2017	Jun. 30, 2017		Dec. 31, 2016
Balance Sheet Components [Abstract]
Cash and cash equivalents	$ 711,157		$ 859,192	$ 823,475
Restricted cash included in other assets	5,512			5,499
Total cash, cash equivalents and restricted cash	716,669	[1]	$ 864,697	828,974	[1]	$ 572,168
Restricted cash, pledged as collateral	4,000			4,000
Restricted cash, letter of credit	$ 1,100			$ 1,100

[1] See Note 3 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.