Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Net sales	$ 9,913	$ 10,735	$ 9,823
Cost of products sold	3,465	3,116	2,813
Gross profit	6,448	7,620	7,011
Operating expenses:
Selling, general and administrative expenses	3,787	3,941	3,569
Research and development expenses	1,143	1,174	1,113
Royalty expense	45	65	70
Amortization expense	789	699	599
Goodwill impairment charges	73	0	0
Intangible asset impairment charges	460	105	35
Contingent consideration net expense (benefit)	(100)	(35)	(21)
Restructuring net charges (credits)	52	38	36
Litigation-related net charges (credits)	278	115	103
Operating expenses	6,528	6,102	5,504
Operating income (loss)	(80)	1,518	1,506
Other income (expense):
Interest expense	(361)	(473)	(241)
Other, net	362	(358)	156
Income (loss) before income taxes	(79)	687	1,422
Income tax (benefit) expense	2	(4,013)	(249)
Net income (loss)	(82)	4,700	1,671
Preferred stock dividends	33	0	0
Net income (loss) available to common stockholders	$ (115)	$ 4,700	$ 1,671
Net income (loss) per common share — basic	$ (0.08)	$ 3.38	$ 1.21
Net income (loss) per common share — assuming dilution	$ (0.08)	$ 3.33	$ 1.19
Weighted-average shares outstanding
Basic	1,416,700	1,391,500	1,381,000
Assuming dilution	1,416,700	1,410,600	1,401,400