Quarterly financial data (unaudited) (Tables)

12 Months Ended

Dec. 31, 2019

Quarterly Financial Information Disclosure [Abstract]

Quarterly financial data (unaudited)

Quarterly financial data is summarized as follows (in millions, except per-share data):

	2019 Quarters ended
	December 31		September 30		June 30		March 31
Product sales	$	5,881	$	5,463	$	5,574	$	5,286
Gross profit from product sales	$	4,628	$	4,427	$	4,562	$	4,231
Net income	$	1,703	$	1,968	$	2,179	$	1,992
Earnings per share:
Basic	$	2.87	$	3.29	$	3.59	$	3.20
Diluted	$	2.85	$	3.27	$	3.57	$	3.18
	2018 Quarters ended
	December 31		September 30		June 30		March 31
Product sales	$	6,001	$	5,510	$	5,679	$	5,343
Gross profit from product sales	$	4,905	$	4,473	$	4,655	$	4,399
Net income	$	1,928	$	1,859	$	2,296	$	2,311
Earnings per share:
Basic	$	3.04	$	2.88	$	3.50	$	3.27
Diluted	$	3.01	$	2.86	$	3.48	$	3.25