Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Accrued Liabilities and Other Current Liabilities [Abstract]
Accrued compensation and benefits	$ 473	$ 322
Accrued property and equipment	192	164
Promissory note payable	201	0
Other current liabilities	583	380
Accrued expenses and other current liabilities	1,449	866
Other Liabilities [Abstract]
Income tax payable	2,458	1,190
Noncurrent deferred tax liability	163	769
Contingent consideration liability	267	193
Other liabilities	269	175
Other liabilities	$ 3,157	$ 2,327