Income taxes (Tables)

12 Months Ended

Dec. 31, 2017

Income Tax Disclosure [Abstract]

Schedule of income before income tax, domestic and foreign

Income before income taxes included the following (in millions):

	Years ended December 31,
	2017		2016		2015
Domestic	$	4,436	$	4,478	$	3,532
Foreign	5,161		4,685		4,446
Total income before income taxes	$	9,597	$	9,163	$	7,978

Provision for income taxes

The provision for income taxes included the following (in millions):

	Years ended December 31,
	2017			2016			2015
Current provision:
Federal	$	8,615		$	984		$	1,129
State	5			65			40
Foreign	275			176			272
Total current provision	8,895			1,225			1,441
Deferred (benefit) provision:
Federal	(1,120		)	372			(290		)
State	—			(69		)	(78		)
Foreign	(157		)	(87		)	(34		)
Total deferred (benefit) provision	(1,277		)	216			(402		)
Total provision for income taxes	$	7,618		$	1,441		$	1,039

Significant components of deferred tax assets and liabilities

Significant components of our deferred tax assets and liabilities were as follows (in millions):

	December 31,
	2017			2016
Deferred income tax assets:
NOL and credit carryforwards	$	812		$	688
Accrued expenses	362			562
Expenses capitalized for tax	155			255
Stock-based compensation	99			167
Other	154			117
Total deferred income tax assets	1,582			1,789
Valuation allowance	(497		)	(381		)
Net deferred income tax assets	1,085			1,408
Deferred income tax liabilities:
Acquired intangible assets	(1,748		)	(3,139		)
Debt	(184		)	(345		)
Other	(240		)	(307		)
Total deferred income tax liabilities	(2,172		)	(3,791		)
Total deferred income taxes, net	$	(1,087	)	$	(2,383	)

Reconciliation of total gross amounts of unrecognized tax benefits (excluding interest, penalties, foreign tax credits and the federal tax benefit of state taxes related to unrecognized tax benefits)

The reconciliations of the total gross amounts of UTBs (excluding interest, penalties, foreign tax credits and the federal tax benefit of state taxes related to UTBs) were as follows (in millions):

	Years ended December 31,
	2017			2016			2015
Beginning balance	$	2,543		$	2,114		$	1,772
Additions based on tax positions related to the current year	447			425			413
Additions based on tax positions related to prior years	1			18			9
Reductions for tax positions of prior years	(5		)	(7		)	(32		)
Reductions for expiration of statute of limitations	(5		)	—			—
Settlements	(28		)	(7		)	(48		)
Ending balance	$	2,953		$	2,543		$	2,114

Reconciliation between the federal statutory tax rate and effective tax rate

The reconciliations between the federal statutory tax rate applied to income before income taxes and our effective tax rate were as follows:

	Years ended December 31,
	2017		2016		2015
Federal statutory tax rate	35.0	%	35.0	%	35.0	%
2017 Tax Act, net repatriation tax	71.5	%	—	%	—	%
Foreign earnings	(15.8	)%	(15.5	)%	(18.1	)%
2017 Tax Act, net deferred tax remeasurement	(7.7	)%	—	%	—	%
Credits, Puerto Rico Excise Tax	(2.2	)%	(2.3	)%	(2.5	)%
Share-based payments	(0.7	)%	(1.3	)%	—	%
Credits, primarily federal R&D	(0.6	)%	(0.7	)%	(1.4	)%
State taxes	0.3	%	0.1	%	0.1	%
Audit settlements (federal, state, foreign)	(0.3	)%	—	%	(0.5	)%
Other, net	(0.1	)%	0.4	%	0.4	%
Effective tax rate	79.4	%	15.7	%	13.0	%