Collaborations and Other Arrangements (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Jun. 30, 2021	Dec. 31, 2020
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue	$ 6,772.8	$ 5,740.6	$ 20,318.5	$ 17,099.8
Contract liabilities	278.4		278.4			$ 276.8
China
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue	400.3	289.1	1,285.0	796.2
Jardiance
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue	390.4	310.8	1,058.9	840.3
Trajenta
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue	96.1	91.7	279.9	261.7
Basaglar
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue	192.8	248.2	650.1	842.3
Olumiant®
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue	406.9	162.0	809.1	446.7
COVID-19 Antibodies
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue		0.0	1,176.2	0.0
Revenue	217.1		1,180.0
Tyvyt®
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue	125.6	$ 84.4	340.2	$ 205.9
Lebrikizumab
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Contract liabilities	15.3		15.3			29.7
Milestone Payments, Development and Regulatory, Capitalized (Deferred), Cumulative | Jardiance
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Potential achievements	141.1		141.1			156.2
Milestone Payments, Development and Regulatory, Capitalized (Deferred), Cumulative | Trajenta
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Potential achievements	95.1		95.1			114.6
Milestone Payments, Development and Regulatory, Capitalized (Deferred), Cumulative | Basaglar
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Potential achievements	(154.0)		$ (154.0)			(168.0)
Royalty Agreement Terms | Olumiant®
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Collaborative arrangement, rights and obligations, percentage (up to)			20.00%
Milestone Payments, Capitalized as Intangible Assets | Junshi Biosciences
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Potential achievements	95.0		$ 95.0
Milestone Payments, Capitalized as Intangible Assets | Olumiant®
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Potential achievements	210.0		210.0			$ 210.0
Milestone Payments, Capitalized as Intangible Assets | Tyvyt®
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Potential achievements					$ 40.0
Milestone Payments, Development and Regulatory | Olumiant®
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Potential achievements	100.0		100.0
Milestone Payments, Development and Regulatory | Lebrikizumab
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Potential achievements	85.0		85.0
Milestone Payments, Sales-based | Junshi Biosciences
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Potential achievements	100.0		100.0
Milestone Payments, Sales-based | Olumiant®
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Potential achievements	150.0		150.0
Milestone Payments, Sales-based | Lebrikizumab
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Potential achievements	1,250.0		1,250.0
Milestone Payments, Contingent Upon Initiation of Phase I Trial | Petra
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Potential achievements	205.0		205.0
Milestone Payments, Contingent Upon Achieving Clinical Proof of Concept | Petra
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Potential achievements	164.0		164.0
Innovent Biologics, Inc. | Milestone Payments, Success-based Regulatory and Sales-based | Tyvyt® | Non-CHINA
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Potential achievements	825.0		825.0
Innovent Biologics, Inc. | Milestone Payments, Success-based Regulatory and Sales-based | Tyvyt® | China
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Potential achievements	195.0		195.0
Roche | Milestone Payments, Development and Regulatory | Lebrikizumab
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Potential achievements	180.0		180.0
Roche | Milestone Payments, Sales-based | Lebrikizumab
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Potential achievements	$ 1,030.0		$ 1,030.0