11. Income taxes

The income tax expense (benefit) by jurisdiction consists of the following for the years ended December 31:

	2016			2015		2014
U.S. federal:
Current	$	55		$	27	$	6
Deferred		345			319		328

Total U.S. federal	$	400		$	346	$	334


U.S. state and local:
Current	$	69		$	134	$	226
Deferred		(42	)		1		140

Total U.S. state and local	$	27		$	135	$	366

Income taxes differ from the amounts computed by applying the U.S. federal income tax rate to pretax income before income taxes as a result of the following for the years ended December 31:

	2016			2015			2014
Federal statutory rate		34.0	%		34.0	%		34.0	%
State and local		2.2			4.1			4.6
Foreign rate differential		(0.4	)		(0.5	)		(0.7	)
Stock options		(1.5	)		(1.5	)		(0.5	)
Excess tax benefits from stock-based compensation		2.8			—			—
Non-controlling interests		0.6			0.5			1.9
Valuation allowance		(38.9	)		(39.0	)		(45.1	)
Uncertain tax positions		(0.2	)		(0.1	)		(0.1	)
Return to provision		—			—			0.6
Other		(0.2	)		0.3			1.4

Income taxes		(1.6	)%		(2.2	)%		(3.9	)%

We have a foreign subsidiary in the United Kingdom, which has generated losses since inception resulting in a $1,660 deferred tax asset with a corresponding valuation allowance as of December 31, 2016. We also have a majority owned foreign subsidiary in Brazil, which has generated losses since inception resulting in a $466 deferred tax asset with a corresponding valuation allowance as of December 31, 2016. Foreign loss before income taxes was $856, $1,381, and $1,251 for 2016, 2015, and 2014, respectively.

Deferred income tax reflects the tax effects of temporary differences that gave rise to significant portions of our deferred tax assets and liabilities and consisted of the following for the years ended December 31:

	2016			2015
Deferred tax assets:
Net operating loss carryforwards	$	23,669		$	16,895
Outside basis differences for U.S. partnerships		16,121			6,190
Stock options		5,307			3,882
Deferred revenue		526			376
Deferred compensation		199			301
State taxes		49			67
Other		1,622			1,312
Valuation allowance		(36,331	)		(19,548	)

Net deferred tax assets		11,162			9,475
Deferred tax liabilities:
Intangible assets		(5,658	)		(6,268	)
Property and equipment		(8,712	)		(6,172	)

Net deferred tax liabilities		(14,370	)		(12,440	)

Net deferred taxes	$	(3,208	)	$	(2,965	)

As noted above, we adopted ASU 2016-09 as of January 1, 2016. As a result of the adoption of ASU 2016-09, excess windfall tax benefits and tax deficiencies related to our stock option exercises and RSU vestings are recognized as an income tax benefit or expense in our consolidated statements of operations in the period they are deducted on the income tax return. Prior to January 1, 2016, excess windfall tax benefits were not included as components of gross deferred tax assets and corresponding valuation allowance disclosures, as tax attributes related to those windfall tax benefits were not recognized until they resulted in a reduction of taxes payable.

In assessing the realizability of deferred tax assets, we consider whether it is more likely than not that some portion or all of the deferred tax assets will not be realized. As of December 31, 2016 and 2015, we had federal net operating loss carryforwards of approximately $55,780 and $55,278, respectively, state net operating loss carryforwards of approximately $56,006 and $68,614, respectively, and foreign net operating loss carryforwards of $9,672 and $9,042, respectively. The federal net operating loss carryforwards will begin to expire in 2025, and our foreign net operating loss carryforwards have an indefinite life. Our state net operating loss carryforwards are principally related to California net operating losses and will begin to expire in 2017. Our ability to utilize certain of our net operating loss carryforwards may be limited in the event that a change in ownership, as defined in the Internal Revenue Code, occurs in the future.

The following table sets forth the changes in the valuation allowance, for all periods presented:

	Valuation Allowance
Balance, December 31, 2013	$	4,101
Additions charged to operations		8,369
Decrease credited to operations		—

Balance, December 31, 2014		12,470
Additions charged to operations		7,078
Decrease credited to operations		—

Balance, December 31, 2015		19,548
Additions charged to operations		16,783
Decrease credited to operations		—

Balance, December 31, 2016	$	36,331

In reaching the determination of the valuation allowance, we have evaluated all significant available positive and negative evidence including, but not limited to, our three year cumulative results, trends in our business, expected future results and the character, amount and expiration periods of our net deferred tax assets. The underlying assumptions we used in forecasting future income required significant judgment and took into account our recent performance.

We recognized interest and penalties related to income tax matters in income taxes. Interest and penalties were not material during the years ended December 31, 2016, 2015, and 2014.

We identify, evaluate and measure all uncertain tax positions taken or to be taken on tax returns and record liabilities for the amount of these positions that may not be sustained, or may only partially be sustained, upon examination by the relevant taxing authorities. Although we believe that our estimates and judgments were reasonable, actual results may differ from these estimates. Some or all of these judgments are subject to review by the taxing authorities. As of December 31, 2016 and 2015, we had $380 and $363 in uncertain tax positions, respectively, $84 of which is a reduction to deferred tax assets, which is presented net of uncertain tax positions, in the accompanying consolidated balance sheets. We accrue interest and penalties related to unrecognized tax benefits as a component of income taxes. As of December 31, 2016 and 2015, we have accrued $67 and $50, respectively for related interest, net of federal income tax benefits, and penalties recorded in income tax expense on our consolidated statements of operations. The amount of unrecognized tax benefits that, if recognized, would affect the effective tax rate at December 31, 2016 was $229.

A reconciliation of our unrecognized tax benefits, excluding interest and penalties, is as follows:

	Uncertain Tax Positions
Balance, December 31, 2014	$	392
Additions for current period tax positions		—
Effective settlement during the current period		(79	)

Balance, December 31, 2015 and 2016	$	313

Our annual income taxes and the determination of the resulting deferred tax assets and liabilities involve a significant amount of judgment. Our judgments, assumptions and estimates relative to current income taxes take into account current tax laws, their interpretation of current tax laws and possible outcomes of current and future audits conducted by foreign and domestic tax authorities. We operate within federal, state and international taxing jurisdictions and are subject to audit in these jurisdictions. These audits can involve complex issues which may require an extended period of time to resolve. We are subject to taxation in the United States and in various states. Our tax years 2013 and forward are subject to examination by the IRS and our tax years 2012 and forward are subject to examination by material state jurisdictions. However, due to prior year loss carryovers, the IRS and state tax authorities may examine any tax years for which the carryovers are used to offset future taxable income.