Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Statement [Abstract]
Revenue	$ 22,871.3	$ 21,222.1	$ 19,958.7
Costs, expenses, and other:
Cost of sales	6,070.2	5,654.9	5,037.2
Research and development	5,281.8	5,243.9	4,796.4
Marketing, selling, and administrative	6,588.1	6,452.0	6,533.0
Acquired in-process research and development (Notes 3 and 4)	1,112.6	30.0	535.0
Asset impairment, restructuring, and other special charges (Note 5)	1,673.6	382.5	367.7
Other—net, (income) expense (Note 17)	(52.4)	84.8	(100.6)
Cost of sales, operating expenses, and other-net	20,673.9	17,848.1	17,168.7
Income before income taxes	2,197.4	3,374.0	2,790.0
Income taxes (Note 13)	2,401.5	636.4	381.6
Net income (loss)	$ (204.1)	$ 2,737.6	$ 2,408.4
Earnings (loss) per share:
Basic (usd per share)	$ (0.19)	$ 2.59	$ 2.27
Diluted (usd per share)	$ (0.19)	$ 2.58	$ 2.26
Shares used in calculation of earnings (loss) per share:
Basic (shares)	1,052,023	1,058,324	1,061,913
Diluted (shares)	1,052,023	1,061,825	1,065,720