Stockholders' Equity Reclassification Out of Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Investment income	$ 94	$ 123	$ 128
Income tax provision	(710)	(868)	(772)
Product revenues	13,514	14,051	13,690
Cost of product sales	(5,809)	(5,738)	(5,650)
Net income	2,172	2,894	3,093
Interest expense	(164)	(147)	(156)
Income before provision for income taxes	2,882	3,762	3,865
Accumulated Net Unrealized Investment Gain (Loss)
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Income tax provision	5	(31)	(18)
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Income tax provision	56	64	66
Accumulated Defined Benefit Plans Adjustment
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Income tax provision	71	70	$ 61
Reclassification out of Accumulated Other Comprehensive Income | Accumulated Defined Benefit Plans Adjustment
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Income tax provision	5	3
Net income	(8)	(6)
Other Cost and Expense, Operating	(13)	(9)
Foreign Exchange Contract | Reclassification out of Accumulated Other Comprehensive Income | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Income tax provision	5	0
Product revenues	30	39
Cost of product sales	(2)	(10)
Net income	11	18
Income before provision for income taxes	6	18
Interest rate swap contract | Reclassification out of Accumulated Other Comprehensive Income | Accumulated Net Gain Loss Interest Rate Swap
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Interest expense	(22)	(11)
Unrealized Gain on Investments [Member] | Reclassification out of Accumulated Other Comprehensive Income | Accumulated Net Unrealized Investment Gain (Loss)
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Investment income	70	62
Income tax provision	(27)	(23)
Net income	$ 43	$ 39