Segment Information - Net Sales Attributed to Foreign Countries (Details) - USD ($) $ in Millions	3 Months Ended																12 Months Ended
	Dec. 31, 2015	[1]	Sep. 30, 2015	[1]	Jun. 30, 2015	[1]	Mar. 31, 2015	[1]	Dec. 31, 2014	[1]	Sep. 30, 2014	[1]	Jun. 30, 2014	[1]	Mar. 31, 2014	[1]	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	$ 35,747		$ 25,358		$ 23,185		$ 22,717		$ 29,328		$ 20,579		$ 19,340		$ 19,741		$ 107,006	$ 88,988	$ 74,452
United States
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales																	70,537	54,717	43,959
Germany
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales																	11,816	11,919	10,535
Japan
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales																	8,264	7,912	7,639
United Kingdom
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales																	9,033	8,341	7,291
Rest of World
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales																	$ 7,356	$ 6,099	$ 5,028

[1] The sum of quarterly amounts, including per share amounts, may not equal amounts reported for year-to-date periods. This is due to the effects of rounding and changes in the number of weighted-average shares outstanding for each period.