	Year Ended December 26,			Year Ended December 31,
	2020			2019			2018
Current:
Federal	$	1,466		$	(27	)	$	4,423
State		371			88			1,038
Foreign		5,637			1,548			626
		7,474			1,609			6,087
Deferred:
Federal		(10,355	)		(4,730	)		1,961
State		(1,036	)		506			(73	)
Foreign		(240	)		108			275
		(11,631	)		(4,116	)		2,163
Total income tax expense (benefit)	$	(4,157	)	$	(2,507	)	$	8,250

	Year Ended December 26,			Year Ended December 31,
	2020			2019			2018
Domestic operations	$	(120	)	$	(7,087	)	$	49,089
Foreign operations	$	26,988		$	6,490		$	4,257

The provision for income taxes differs from the amount of income tax determined by applying the applicable U.S. federal income tax rate of 21% for the years ended December 26, 2020, December 31, 2019 and December 31, 2018, to income before provision for income taxes as follows:

	Year Ended December 26,			Year Ended December 31,
	2020			2019			2018
Federal income tax provision (benefit) at statutory rate	$	5,642		$	(125	)	$	11,203
State taxes, net of federal effect		126			113			747
Foreign taxes, net of federal effect		596			(1,277	)		17
Foreign Derived Intangible Income ("FDII") Deduction		(4,262	)		(2,278	)		(2,217	)
Global Intangible Low-Taxes Income ("GILTI") inclusion		2,013			1,786			113
Non-deductible officer's compensation		213			826			526
Research & development tax credit		(4,858	)		(2,126	)		(2,298	)
Tax impact of IRS audit closure		(2,905	)		—			—
Impact of the Tax Act		—			—			105
Impact of the CARES Act		(1,141	)		—			—
Other		419			574			54
Provision (benefit) for income taxes	$	(4,157	)	$	(2,507	)	$	8,250
Effective tax rate		(16	)%		(420	)%		15	%

	December 26,			December 31,
	2020			2019
Deferred Tax Assets:
Reserves and accruals	$	13,874		$	8,254
Deferred revenue		1,648			1,219
Share-based compensation		2,556			2,955
Tax credit carryforward		10,801			11,307
Net operating losses		4,849			6,008
Depreciation and amortization		687			946
Operating lease liabilities		4,261			4,965
Other		1,877			772
Gross deferred tax assets		40,553			36,426
Less: valuation allowance		(14,238	)		(14,160	)
Total deferred tax assets after valuation allowance		26,315			22,266
Deferred Tax Liabilities:
Depreciation and amortization		(75,608	)		(83,082	)
Operating lease right of use assets		(3,960	)		(4,709	)
Other		(135	)		(59	)
Gross deferred tax liabilities		(79,703	)		(87,850	)
Net deferred tax liabilities	$	(53,388	)	$	(65,584	)

At December 26, 2020 and December 31, 2019, the Company had recorded valuation allowances of $14,238 and $14,160, respectively, on a certain portion of the Company’s deferred tax assets to reflect the deferred tax assets at the net amount that is more likely than not to be realized. The Company maintained a full valuation allowance against its Switzerland and United Kingdom deferred tax assets of $2,797 and $467, respectively. The Company also maintained a valuation allowance against a portion of its federal and California deferred tax assets of $3,150 and $7,824, respectively.

In assessing the realizability of deferred tax assets, the Company uses a more likely than not standard. If it is determined that it is more-likely-than-not that deferred tax assets will not be realized, a valuation allowance must be established against the deferred tax assets. The ultimate realization of the assets is dependent on the generation of future taxable income during the periods in which the associated temporary differences become deductible. Management considers the scheduled reversal of deferred income tax liabilities, projected future taxable income and tax planning strategies when making this assessment. In making the determination that it is more likely than not that the Company’s deferred tax assets will be realized as of

December 26, 2020, the Company relied primarily on the reversal of deferred tax liabilities as well as projected future taxable income.

At December 26, 2020, the Company had federal, state and foreign net operating loss carryforwards of $85, $1,892 and $2,873, respectively. The federal, state and foreign net operating loss carryforwards expire on various dates beginning in 2020 through 2035.

At December 26, 2020, the Company had federal and state research & development credits and foreign tax credit carryforwards of $5,731, $10,664 and $3,150, respectively. The state research & development credits are set to expire at various dates beginning in 2039. The foreign tax credit is set to expire at various dates through December 31, 2029.

As of December 26, 2020, the Company has provided U.S. income taxes on all its foreign earnings. The Company continues to permanently reinvest the cash held offshore to support its working capital needs. Accordingly, no additional foreign withholding taxes that may be required from certain jurisdictions in the event of a cash distribution have been provided for.

	December 26,			December 31,
	2020			2019			2018
Balance, beginning of the period	$	15,143		$	5,528		$	4,880
Gross increases—tax positions in prior period		347			9,989			496
Gross decreases—tax positions in prior period		—			(932	)		(61	)
Gross increases—current-period tax positions		1,048			558			213
Closure of audit/statute limitation		(3,052	)		—			—
Balance, end of the period	$	13,486		$	15,143		$	5,528

The unrecognized tax benefit at December 26, 2020 and December 31, 2019 were $13,486 and $15,143, respectively, of which $8,863 and $10,649, respectively, would be reflected as an adjustment to income tax expense if recognized. The year over year decrease from 2019 to 2020 is primarily due to the closure of IRS audit for tax years 2016 through 2018, offset by additional unrecognized tax benefits related to federal tax exposures. It is reasonably possible that certain amounts of unrecognized tax benefits may reverse in the next 12 months; however, the Company does not expect such reversals to have a significant impact on its results of operations or financial position.

The Company recognizes accrued interest and penalties related to unrecognized tax benefits in income tax expense. During the years ended December 26, 2020, December 31, 2019 and December 31, 2018, the Company recognized approximately $(193), $236 and $199, respectively, in interest and penalties (benefit) expense associated with uncertain tax positions. As of December 26, 2020 and December 31, 2019, the Company had accrued interest and penalties expense included in the table of unrecognized tax benefits of $1,487 and $1,681, respectively.

The Company is subject to U.S. federal income tax as well as income tax in multiple state and foreign jurisdictions. The Company is subject to ordinary statute of limitation rules of three and four years for federal and state returns, respectively. However, due to tax attribute carryforwards, the Company is subject to examination for tax years 2003 forward for U.S. federal tax purposes with respect to carryforward amounts. The Company is also subject to examination in various states for tax years 2002 forward with respect to carryforward amounts. The Company is subject to examination for tax years 2010 forward for various foreign jurisdictions. The Company believes that adequate amounts have been reserved for any adjustments that may ultimately result from any future examinations of these years.

In the normal course of business, the Company is subject to tax audits in various jurisdictions, and such jurisdictions may assess additional income taxes or other taxes against it. Although the Company believes its tax estimates are reasonable, the final determination of tax audits and any related litigation could be materially different from the Company’ s historical income tax provisions and accruals. The results of an audit or litigation could have a material adverse effect on the Company’ s results of operations or cash flows in the period or periods for which that determination is made.