Collaborations and Other Arrangements (Net Product Revenue) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue	$ 24,539.8	$ 22,319.5	$ 21,493.3
Basaglar®
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue	1,124.4	1,112.6	801.2
Jardiance
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue	1,153.8	944.2	658.3
Trajenta®
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue	358.5	590.6	574.7
Olumiant®
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue	$ 638.9	$ 426.9	$ 202.5