Balance Sheet Account Detail - Summary of Cash and Cash Equivalents and Marketable Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Schedule of Investments [Line Items]
Cost of equity securities	$ 6,310	$ 6,310
Foreign currency translation on equity securities	(2,789)	(2,477)
Equity securities, Unrealized Gains	16,976	27,214
Equity securities, Unrealized Losses	0	0
Equity securities (Note 7)	20,497	31,047
Cash, cash equivalents and short-term investments, amortized cost	163,692	198,309
Total cash and cash equivalents and marketable securities, Unrealized Gains	17,347	28,076
Total cash and cash equivalents and marketable securities, Unrealized Losses	(457)	(35)
Cash, cash equivalents, and short-term investments	177,793	223,873
Cash and Cash Equivalents
Schedule of Investments [Line Items]
Equity securities (Note 7)	0	0
Cash, cash equivalents, and short-term investments	70,352	64,418
Marketable Securities
Schedule of Investments [Line Items]
Equity securities (Note 7)	20,497	31,047
Cash, cash equivalents, and short-term investments	107,441	159,455
Bank deposits
Schedule of Investments [Line Items]
Available-for-sale, debt securities, amortized cost	6,070	5,219
Debt securities, available-for-sale, unrealized gain	0	0
Debt securities, available-for-sale, unrealized loss	0	0
Available-for-sale, debt securities, estimated fair value	6,070	5,219
Bank deposits \| Cash and Cash Equivalents
Schedule of Investments [Line Items]
Available-for-sale, debt securities, estimated fair value	6,070	5,219
Bank deposits \| Marketable Securities
Schedule of Investments [Line Items]
Available-for-sale, debt securities, estimated fair value	0	0
Money market funds
Schedule of Investments [Line Items]
Available-for-sale, debt securities, amortized cost	54,282	54,199
Debt securities, available-for-sale, unrealized gain	0	0
Debt securities, available-for-sale, unrealized loss	0	0
Available-for-sale, debt securities, estimated fair value	54,282	54,199
Money market funds \| Cash and Cash Equivalents
Schedule of Investments [Line Items]
Available-for-sale, debt securities, estimated fair value	54,282	54,199
Money market funds \| Marketable Securities
Schedule of Investments [Line Items]
Available-for-sale, debt securities, estimated fair value	0	0
Government-related debt securities
Schedule of Investments [Line Items]
Available-for-sale, debt securities, amortized cost	50,113	62,617
Debt securities, available-for-sale, unrealized gain	324	19
Debt securities, available-for-sale, unrealized loss	0	(10)
Available-for-sale, debt securities, estimated fair value	50,437	62,626
Government-related debt securities \| Cash and Cash Equivalents
Schedule of Investments [Line Items]
Available-for-sale, debt securities, estimated fair value	10,000	0
Government-related debt securities \| Marketable Securities
Schedule of Investments [Line Items]
Available-for-sale, debt securities, estimated fair value	40,437	62,626
Corporate debt securities
Schedule of Investments [Line Items]
Available-for-sale, debt securities, amortized cost	33,888	58,235
Debt securities, available-for-sale, unrealized gain	15	38
Debt securities, available-for-sale, unrealized loss	(159)	(25)
Available-for-sale, debt securities, estimated fair value	33,744	58,248
Corporate debt securities \| Cash and Cash Equivalents
Schedule of Investments [Line Items]
Available-for-sale, debt securities, estimated fair value	0	5,000
Corporate debt securities \| Marketable Securities
Schedule of Investments [Line Items]
Available-for-sale, debt securities, estimated fair value	33,744	53,248
Mutual funds
Schedule of Investments [Line Items]
Available-for-sale, debt securities, amortized cost	4,941	4,375
Debt securities, available-for-sale, unrealized gain	0	783
Debt securities, available-for-sale, unrealized loss	(298)	0
Available-for-sale, debt securities, estimated fair value	4,643	5,158
Mutual funds \| Cash and Cash Equivalents
Schedule of Investments [Line Items]
Available-for-sale, debt securities, estimated fair value	0	0
Mutual funds \| Marketable Securities
Schedule of Investments [Line Items]
Available-for-sale, debt securities, estimated fair value	4,643	5,158
Bank CDs
Schedule of Investments [Line Items]
Available-for-sale, debt securities, amortized cost	8,088	7,354
Debt securities, available-for-sale, unrealized gain	32	22
Debt securities, available-for-sale, unrealized loss	0	0
Available-for-sale, debt securities, estimated fair value	8,120	7,376
Bank CDs \| Cash and Cash Equivalents
Schedule of Investments [Line Items]
Available-for-sale, debt securities, estimated fair value	0	0
Bank CDs \| Marketable Securities
Schedule of Investments [Line Items]
Available-for-sale, debt securities, estimated fair value	$ 8,120	$ 7,376

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