Amount of assets, excluding financial assets and goodwill, that lack physical substance, having a projected indefinite period of benefit, acquired at the acquisition date.

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The amount of identifiable intangible assets recognized as of the acquisition date.

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Amount recognized for assets, including goodwill, in excess of (less than) the aggregate liabilities assumed.

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Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Business Combinations - Net Assets Acquired (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016	Jun. 02, 2016
Identifiable assets acquired
Goodwill	$ 785	$ 785
Lesinurad transaction \| AstraZeneca
Identifiable assets acquired
Goodwill			$ 785
Net assets acquired			167,885
Lesinurad transaction \| AstraZeneca \| IPR&D - DUZALLO
Identifiable assets acquired
In-process research and development			145,100
Lesinurad transaction \| AstraZeneca \| Developed technology - ZURAMPIC
Identifiable assets acquired
Developed technology			$ 22,000