CONSOLIDATED FINANCIAL STATEMENT DETAILS - Cash, Cash Equivalents, and Restricted Cash (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Cash and cash equivalents	$ 3,151,959	$ 2,131,632	$ 1,644,829	$ 1,630,809
Restricted cash included in other current assets	1,574	1,633	347	2,873
Restricted cash included in other non-current assets	420	420	0	0
Total cash, cash equivalents and restricted cash as shown on the consolidated statement of cash flows	$ 3,153,953	$ 2,133,685	$ 1,645,176	$ 1,633,682