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Business combination risk adjusted discount rates used to calculate present value of future expected cash inflows of intangible assets.

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Excess Inventory Purchase Commitments Expense (Reversal)

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Fair value of subsidiary or equity method investee cumulative number of additional shares issued for all transactions.

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Subsidiary or equity method investee cumulative number of additional shares expected to be issued for all transactions.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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The amount of goodwill arising from a business combination that is expected to be deductible for tax purposes.

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Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

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Amount of deferred tax liability attributable to taxable temporary differences assumed at 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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The value of the financial instrument(s) that the original debt is being converted into in a noncash (or part noncash) transaction. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period.

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The number of shares issued in exchange for the original debt being converted in a noncash (or part noncash) transaction. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or payments in the period.

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Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Ratio applied to the conversion of stock split, for example but not limited to, one share converted to two or two shares converted to one.

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Business Combination - Additional Information (Details)			3 Months Ended		6 Months Ended		12 Months Ended
Business Combination - Additional Information (Details)	Dec. 12, 2018 USD ($)	Dec. 11, 2018 USD ($)	Jun. 30, 2020 USD ($)	Mar. 31, 2020	Jun. 30, 2020 USD ($) shares	Jun. 30, 2019 USD ($)	Dec. 31, 2019
Business Acquisition [Line Items]
Total fair value consideration	$ 527,754,000
Impairment of intangible asset, finite-lived			$ 115,500,000
Increase in excess inventory purchase commitments					$ 10,954,000	$ 0
BioVectra Inc
Business Acquisition [Line Items]
Preliminary fair value of the off-market element	29,500,000
Increase in excess inventory purchase commitments			$ 11,000,000.0
Developed Product Rights for Auryxia
Business Acquisition [Line Items]
Intangible assets, estimated useful life			7 years	9 years	7 years		9 years
Keryx Biopharmaceuticals, Inc.
Business Acquisition [Line Items]
Total fair value consideration	527,754,000
Business combination, Purchase price	$ 527,754,000
Risk-adjusted discount rate used to calculate present value of future expected cash inflows of intangible assets	20.00%
Preliminary fair value of the off-market element	$ 29,510,000
Goodwill deductible for tax purposes	0
Deferred tax liability	$ 35,096,000
Keryx Biopharmaceuticals, Inc. \| Developed Product Rights for Auryxia
Business Acquisition [Line Items]
Intangible assets, estimated useful life	9 years		7 years
Keryx Biopharmaceuticals, Inc. \| Common Stock
Business Acquisition [Line Items]
Total fair value consideration	$ 516,492,000
Keryx Biopharmaceuticals, Inc. \| Merger Agreement
Business Acquisition [Line Items]
Outstanding common stock and awards converted into right to receive shares and awards, ratio	0.37433				0.37433
Total fair value consideration	$ 527,800,000
Additional shares expected to be issued (in shares) \| shares					4,000,000
Aggregate shares available for conversion (in shares) \| shares					39,600,000
Fair value of additional shares issued					$ 13,400,000
Keryx Biopharmaceuticals, Inc. \| Notes Conversion Agreement
Business Acquisition [Line Items]
Convertible notes amount		$ 164,700,000
Keryx Biopharmaceuticals, Inc. \| Notes Conversion Agreement \| Common Stock
Business Acquisition [Line Items]
Convertible notes converted into shares (in shares) \| shares					35,582,335