Legal Matters (Details)	Jul. 16, 2020 claim	Jul. 31, 2017 claim	Sep. 26, 2016 EUR (€)	Feb. 11, 2020 request	Feb. 25, 2019 claim	Feb. 14, 2019 claim
Amgen v.s. Regeneron | Pending Litigation
Loss Contingencies [Line Items]
Loss contingency, damages sought, per unit produced | €			€ 10,000
Loss contingency, damages sought | €			€ 10,000,000.0
'165 Patent | Amgen v.s. Regeneron | Pending Litigation
Loss Contingencies [Line Items]
Pending claims					2
Invalid claims					2
'741 Patent | Amgen v.s. Regeneron | Pending Litigation
Loss Contingencies [Line Items]
Pending claims					1
'487 Patent
Loss Contingencies [Line Items]
Number of IPR filed		2
Number of claims invalidated						17
'631 Patent
Loss Contingencies [Line Items]
Number of IPR filed	2
'226 and '992 Patents | EYLEA
Loss Contingencies [Line Items]
Number of ex parte reexamination requests | request				2