Income Taxes - Deferred Income Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Deferred tax assets:
Loss carryforwards U.S. - Federal/States	$ 222	$ 211
Loss carryforwards - Foreign	2,551	2,149
Accrued liabilities, reserves, and other expenses	1,064	901
Stock-based compensation	1,293	1,026
Deferred revenue	321	349
Assets held for investment	69	35
Depreciation and amortization	2,386	279
Other items	94	167
Tax credits	734	381
Total gross deferred tax assets	8,734	5,498
Less valuation allowance	(4,950)	(2,538)
Deferred tax assets, net of valuation allowance	3,784	2,960
Deferred tax liabilities:
Depreciation and amortization	(3,579)	(2,568)
Acquisition related intangible assets	(682)	(531)
Other items	(67)	(58)
Net deferred tax liabilities, net of valuation allowance	$ (544)	$ (197)