Basis of Presentation (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Basis of Presentation
Cash, cash equivalents and marketable securities	$ 206,900				$ 206,900
Net Loss	(11,031)	$ (12,625)	$ (11,779)	$ (17,239)	(23,656)	$ (29,018)
Net cash used in operations					23,332	$ 24,275
Indefinite-lived intangible assets	$ 45,200				$ 45,200		$ 48,700

Amount of assets, excluding financial assets and goodwill, lacking physical substance and having a projected indefinite period of benefit.

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Sum of investments and unrestricted cash as of the balance sheet date.

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Amount of cash inflow (outflow) from operating activities, including discontinued operations. Operating activity cash flows include transactions, adjustments, and changes in value not defined as investing or financing activities.

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Amount, after deduction of tax, noncontrolling interests, dividends on preferred stock and participating securities; of income (loss) available to common shareholders.

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