CONSOLIDATED FINANCIAL STATEMENT DETAILS - Cash, Cash Equivalents, and Restricted Cash (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Cash and cash equivalents	$ 129,294	$ 465,676	$ 266,374	$ 186,947
Restricted cash included in other current assets	127	127	130	193
Cash, cash equivalents, and restricted cash included in current assets of discontinued operations	0	2,674,146	2,887,029	1,946,125
Restricted cash included in non-current assets of discontinued operations	0	409	420	420
Total cash, cash equivalents, and restricted cash as shown on the consolidated statement of cash flows	$ 129,421	$ 3,140,358	$ 3,153,953	$ 2,133,685