14. Income Taxes

Significant components of deferred tax assets and liabilities are as follows:

	Year Ended December 31,
	2015			2014
Deferred tax assets
Allowance for doubtful accounts	$	17,953		$	14,088
Accrued vacation and bonus		37,481			22,021
Deferred rent		13,415			15,036
Share-based compensation		30,037			18,617
Notes receivable from employees		20,353			23,158
State net operating loss carryforward & credits		3,883			3,558
Foreign net operating loss carryforward		6,614			8,040
Foreign tax credits		—			2,929
Future foreign tax credit asset		3,753			5,259
Deferred compensation		2,279			4,669
Other - net		3,754			9,583
Total deferred tax assets		139,522			126,958
Deferred tax liabilities
Revenue recognition		(12,452	)		(9,402	)
Property, equipment and capitalized software		(5,739	)		(4,142	)
Goodwill and other intangible asset amortization		(247,951	)		(233,572	)
Total deferred tax liabilities		(266,142	)		(247,116	)
Valuation allowance		(13,167	)		(14,442	)
Net deferred tax assets (liabilities)	$	(139,787	)	$	(134,600	)

As of December 31, 2015, we have not provided for deferred taxes on $46.8 million of the undistributed non-U.S. subsidiary earnings that are considered permanently invested. If these earnings were distributed in the form of dividends or otherwise, the distributors would be subject to U.S. federal income tax of approximately $16.4 million.

At December 31, 2015 and 2014, the Company believed certain deferred tax assets principally associated with foreign net operating loss, foreign tax credit carryforwards, and other related foreign balance sheet accounts which can be carried forward for periods ranging from 20 years to indefinite, would expire unused based on updated forward-looking financial information. Therefore, valuation allowances of $13.2 million and $14.4 million were recorded against the Company’s net deferred tax assets at December 31, 2015 and 2014, respectively.

As of December 31, 2015, we have not recorded a $7.6 million deferred tax liability related to the tax basis difference in the investment in our foreign subsidiaries as the investment is considered permanent in duration.

The components of “Income before income tax provision” from continuing operations are as follows:

	Year Ended December 31,
	2015		2014		2013
Domestic	$	59,408	$	60,315	$	32,498
Foreign		45,978		41,096		(687	)
Total	$	105,386	$	101,411	$	31,811

The components of income tax provision from continuing operations are as follows:

	Year Ended December 31,
	2015		2014			2013
Current
Federal	$	23,957	$	288		$	16,066
State		1,943		4,681			6,673
Foreign		10,029		14,042			9,599
		35,929		19,011			32,338
Deferred
Federal	$	1,546	$	21,657		$	(1,094	)
State		1,265		2,309			(1,054	)
Foreign		593		(373	)		12,215
		3,404		23,593			10,067
Income tax provision	$	39,333	$	42,604		$	42,405

Our income tax provision from continuing operations resulted in effective tax rates that varied from the statutory federal income tax rate as follows:

	Year Ended December 31,
	2015			2014			2013
Income tax expense at federal statutory rate	$	36,885		$	35,494		$	11,134
State income taxes, net of federal benefit		1,587			3,494			3,270
Benefit from lower foreign tax rates		(5,973	)		(4,154	)		(5,214	)
Non-deductible goodwill impairment		—			—			29,313
Valuation allowance on foreign tax credits & net operating loss carryforward		2,326			4,604			8,206
Other expenses not deductible for tax purposes		2,719			2,962			2,872
Changes in non-taxable contingent consideration		—			—			(2,777	)
Other adjustments, net		1,789			204			(4,399	)
Income tax provision	$	39,333		$	42,604		$	42,405

We file numerous consolidated and separate income tax returns in the U.S. federal jurisdiction and in many city, state and foreign jurisdictions. We are currently under an IRS audit for the year 2012 and are no longer subject to U.S. federal income tax examinations for years prior to 2011. We are also no longer subject to state and local or foreign tax examinations by tax authorities for years prior to 2009. In addition, open tax years related to state and foreign jurisdictions remain subject to examination but are not considered material to our financial position, results of operations or cash flows.

Our liability for uncertain tax positions was $8.1 million and $2.8 million at December 31, 2015 and 2014, respectively. The $5.3 million increase in our liability for uncertain tax positions was due to the timing of tax deductions claimed in prior years. At December 31, 2015, our accrual for the payment of tax- related interest and penalties was not material. Management believes that an adequate provision has been made for any adjustments that may result from tax examinations. Although the timing of the resolution and closure of such examinations is not certain, the Company believes it is reasonably possible that tax audit resolutions could reduce its unrecognized tax benefits by approximately $5.8 million in the next 12 months.