Additional milestone payment.

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- Definition

Additional reduction in royalty rate payable on commercial sales

+ References

No definition available.

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- Definition

Collaboration Agreement Term

+ References

No definition available.

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- Definition

Investment in biotechnology companies that are determined to be unconsolidated variable interest entities.

+ References

No definition available.

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- Definition

Percentage of future development costs related to Eisai

+ References

No definition available.

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- Definition

Potential future milestone payments commitment to third party approximately.

+ References

No definition available.

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- Definition

Reduction in royalty rate payable on commercial sales

+ References

No definition available.

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- Definition

Research and Development Costs, Percentage

+ References

No definition available.

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- Definition

Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards.

+ References

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- Definition

Amount, after allocation of valuation allowances and deferred tax liability, of deferred tax asset attributable to deductible differences and carryforwards, without jurisdictional netting.

+ References

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- Definition

Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized.

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- Definition

Amount of income (loss) for proportionate share of equity method investee's income (loss).

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- Definition

Amount of cash outflow to a noncontrolling interest. Includes, but not limited to, reduction of noncontrolling interest ownership. Excludes dividends paid to the noncontrolling interest.

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- Definition

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.

+ References

No definition available.

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Investments in Variable Interest Entities (Details) - USD ($) $ in Millions	1 Months Ended			3 Months Ended		6 Months Ended
	Jun. 30, 2021	May 31, 2018	Oct. 31, 2017	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Variable Interest Entity [Line Items]
Payments to Noncontrolling Interests						$ 94.8	$ 0.0
Loss on equity method investment						16.1	(1.6)
Deferred tax assets, net	$ 500.0			$ 500.0		500.0
Deferred tax assets, gross	875.0			875.0		875.0
Deferred tax assets, unrecognized tax benefit	375.0			375.0		375.0
Investment in biotechnology companies that are determined to be unconsolidated variable interest entities	15.2			15.2		$ 15.2		$ 12.8
Neurimmune
Variable Interest Entity [Line Items]
Collaboration agreement term						12 years
Research and development costs, percentage						100.00%
Payments to Noncontrolling Interests		$ 50.0	$ 150.0
Reduction in royalty rate payable on commercial sales			15.00%
Additional reduction in royalty rate payable on commercial sales		5.00%
Regulatory Milestones \| Neurimmune
Variable Interest Entity [Line Items]
Potential future milestone payments commitment to third party								$ 75.0
Eisai
Variable Interest Entity [Line Items]
Loss on equity method investment				$ 40.1	$ 33.8
Percentage of future development costs related to Eisai				45.00%	45.00%
Additional milestone payment					$ 75.0
Eisai \| ADUHELM
Variable Interest Entity [Line Items]
Loss on equity method investment				$ 45.0		$ 45.0
Additional milestone payment	100.0			100.0	$ 75.0	100.0	$ 75.0
Eisai \| Regulatory Milestones \| Neurimmune \| ADUHELM
Variable Interest Entity [Line Items]
Potential future milestone payments commitment to third party	100.0			100.0		100.0
Eisai \| Regulatory Milestones \| JAPAN \| ADUHELM
Variable Interest Entity [Line Items]
Potential future milestone payments commitment to third party	50.0			50.0		50.0
Eisai \| Regulatory Milestones \| Europe \| ADUHELM
Variable Interest Entity [Line Items]
Potential future milestone payments commitment to third party	$ 50.0			$ 50.0		$ 50.0