Income Taxes (Details)	3 Months Ended	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Reconciliation between the U.S. federal statutory tax rate and effective tax rate
Statutory rate	21.00%	21.00%	21.00%	21.00%
State taxes	0.40%	0.90%	0.50%	0.60%
Taxes on foreign earnings	(3.40%)	(4.60%)	(3.70%)	(4.60%)
Credits and net operating loss utilization	(1.00%)	(0.90%)	(1.00%)	(0.80%)
Purchased intangible assets	0.20%	0.40%	0.20%	0.40%
Denmark assets held for sale	0.00%	0.00%	0.00%	2.20%
Internal reorganization of certain intellectual property rights	0.00%	(5.00%)	0.00%	(2.40%)
TECFIDERA impairment	2.70%	0.00%	1.50%	0.00%
GILTI	1.50%	1.40%	1.10%	1.70%
Permanent items	0.10%	0.40%	0.10%	0.30%
Other	0.40%	0.50%	0.10%	0.10%
Effective tax rate	21.90%	14.10%	19.80%	18.50%

Effective Income Tax Rate Reconciliation, Intellectual Property Rights Reorganization

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Effective Tax Rate Reconciliation, GILTI tax

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Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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