CONSOLIDATED FINANCIAL STATEMENT DETAILS - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Variable Interest Entity [Line Items]
Unrealized gains, net, on equity securities held	$ 29,369	$ 126,414	$ 29,247	$ 126,559
Realized gains, net, for equity securities sold	2,066	27,275	2,144	27,172
Interest income	14,500	7,000	26,900	12,200
Realized gain (loss) on disposition of business			(8,200)
Net foreign currency exchange gains (losses)	(2,100)	10,000		2,100
Pinterest
Variable Interest Entity [Line Items]
Unrealized gains, net, on equity securities held	$ 29,800	128,800	$ 29,800	128,800
Realized gains, net, for equity securities sold		$ 26,800		$ 26,800

Amount of realized gain (loss) from sale of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 321
-SubTopic 10
-Section 50
-Paragraph 4
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Amount of unrealized gain (loss) on investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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Amount before tax of foreign currency transaction realized gain (loss) recognized in the income statement.

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Amount of gain (loss) from sale and disposal of integrated set of activities and assets capable of being conducted and managed for purpose of providing return in form of dividend, lower cost, or other economic benefit to investor, owner, member and participant.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
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