Income Taxes Deferred Income Tax Assets and Liabilities (Details) - USD ($) $ in Millions		Dec. 31, 2016	Dec. 31, 2015
Deferred tax assets (1):
Loss carryforwards U.S. - Federal/States (2)	[1],[2]	$ 198	$ 107
Loss carryforwards - Foreign (3)	[1],[3]	1,062	856
Accrued liabilities, reserves, & other expenses		968	854
Stock-based compensation		1,073	727
Deferred revenue		330	189
Assets held for investment		66	148
Depreciation and amortization		179	222
Other items		171	268
Tax credits	[1],[4]	39	41
Total gross deferred tax assets		4,086	3,412
Less valuation allowance	[5]	(1,012)	(1,069)
Deferred tax assets, net of valuation allowance		3,074	2,343
Deferred tax liabilities:
Depreciation & amortization		(2,332)	(1,970)
Acquisition related intangible assets		(226)	(203)
Other items		(62)	(88)
Net deferred tax assets, net of valuation allowance		454	82
Stock Based Compensation Expense
Deferred tax assets (1):
Loss carryforwards U.S. - Federal/States (2)		18	380
Loss carryforwards - Foreign (3)		9	2
Tax credits		$ 659	$ 447

[1] Deferred tax assets related to net operating losses and tax credits are presented net of tax contingencies.

[2] Excluding $380 million and $18 million of deferred tax assets as of December 31, 2015 and 2016, related to net operating losses that result from excess stock-based compensation and for which any benefit realized will be recorded to stockholders’ equity.

[3] Excluding $2 million and $9 million of deferred tax assets as of December 31, 2015 and 2016, related to net operating losses that result from excess stock-based compensation and for which any benefit realized will be recorded to stockholders’ equity.

[4] Excluding $447 million and $659 million of deferred tax assets as of December 31, 2015 and 2016, related to tax credits that result from excess stock-based compensation and for which any benefit realized will be recorded to stockholders’ equity.

[5] Relates primarily to deferred tax assets that would only be realizable upon the generation of net income in certain foreign taxing jurisdictions and future capital gains.