Other Comprehensive Income and Accumulated Other Comprehensive Income (Significant Reclassifications from AOCI) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Net product sales	$ 859	$ 798	$ 2,640	$ 2,251
Investment income	5	5	13	8
Income before income taxes	58	159	458	472
Income tax provision	20	(65)	(45)	(166)
Net income	78	94	413	306
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Net product sales	(1)	13	31	51
Other income (expense)	0	0	(1)	0
Income before income taxes	(1)	13	30	51
Income tax provision	0	(5)	(11)	(18)
Net income	$ (1)	$ 8	$ 19	$ 33