Income Taxes (Details 2) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Difference between income taxes computed at the U.S. federal statutory income tax rate and the income tax expense (benefit)
Federal income tax provision at statutory rate	$ 392	$ 343	$ 462
Statutory income tax rate	35.00%	35.00%	35.00%
State taxes, net of federal benefit	$ 5	$ 5	$ 6
State taxes, net of federal benefit	0.00%	0.00%	0.00%
Research and development credits	$ (26)	$ (24)	$ (49)
Research and development credits	(2.00%)	(2.00%)	(4.00%)
Foreign rate differential	$ (228)	$ (245)	$ (174)
Foreign rate differential	(20.00%)	(25.00%)	(13.00%)
Change in tax reserves	$ 136	$ 128	$ 89
Change in tax reserves	12.00%	13.00%	7.00%
Net operating loss tax attribute received from Purchase Transaction	$ (63)	$ (52)	$ (16)
Net operating loss tax attribute received from Purchase Transaction	(6.00%)	(5.00%)	(1.00%)
Other	$ 13	$ (9)	$ (9)
Other	1.00%	(1.00%)	(1.00%)
Income tax expense	$ 229	$ 146	$ 309
Total	20.00%	15.00%	23.00%