7. Income Taxes

The components of income before income taxes are as follows


	Years ended December 31,
	2018		2017		2016
	(in thousands)
United States	$	55,117	$	35,050	$	21,634
Foreign		1,157		961		2,312
Income before income taxes	$	56,274	$	36,011	$	23,946

The components of income tax expense (benefit) for the three years ended December 31, 2018 were as follows:


	Federal		State		Foreign		Total
	(in thousands)
2018
Current	$	—	$	364	$	622	$	986
Deferred		12,871		(814)		—		12,057
Total	$	12,871	$	(450)	$	622	$	13,043

2017
Current	$	(58)	$	284	$	20	$	246
Deferred		(31,198)		4,805		—		(26,393)
Total	$	(31,256)	$	5,089	$	20	$	(26,147)

2016
Current	$	324	$	14	$	440	$	778
Deferred		8,807		292		—		9,099
Total	$	9,131	$	306	$	440	$	9,877

The following is a reconciliation of the federal income tax expense (benefit) at the statutory rate of 21% (34% for the years ended December 31, 2017 and 2016, respectively) to the effective income tax expense:


	Years Ended December 31,
	2018		2017		2016
	(in thousands)
Statutory federal income tax expense	$	11,818	$	12,244	$	8,142
State taxes, net of federal benefit		(526)		3,360		202
Foreign tax paid		622		20		440
Change in federal tax rate		—		(43,643)		—
Tax consequences of the sale of equipment to WMES		—		164		—
Uncertain tax positions		—		—		(40)
Permanent differences-nondeductible executive compensation		1,144		1,238		1,201
Permanent differences and other		(15)		470		(68)
Effective income tax expense (benefit)	$	13,043	$	(26,147)	$	9,877

The Company records tax expense or benefit for unusual or infrequent items discretely in the period in which they occur.

The following table summarizes the activity related to the Company’s unrecognized tax benefits:


	(in thousands)
Balance as of December 31, 2015	$	274
Increases related to current year tax positions		4
Decreases due to tax positions released		(72)
Balance as of December 31, 2016		206
Increases related to current year tax positions		4
Decreases due to tax positions expired		(19)
Balance as of December 31, 2017		191
Increases related to current year tax positions		—
Decreases due to tax positions expired		(9)
Balance as of December 31, 2018	$	182

No reserve was established as of December 31, 2018 and December 31, 2017 for the exposure in Europe. If the Company is able to eventually recognize these uncertain tax positions, all of the unrecognized benefit would reduce the Company’s effective tax rate.

The tax effects of temporary differences that give rise to significant portions of the deferred tax assets and liabilities are presented below:


	As of December 31,
	2018		2017
	(in thousands)
Deferred tax assets:
Unearned lease revenue	$	1,094	$	1,754
State taxes		77		1,653
Reserves and allowances		1,187		2,531
Other accruals		3,795		643
Alternative minimum tax credit		—		—
Foreign tax credit		26		42
Net operating loss carry forward		39,996		29,874
Charitable contributions		38		22
Total deferred tax assets		46,213		36,519
Less: valuation allowance		(652)		(806)
Net deferred tax assets		45,561		35,713

Deferred tax liabilities:
Depreciation and impairment on aircraft engines and equipment		(133,453)		(114,347)
Other deferred tax assets (liabilities)		(2,365)		437
Net deferred tax liabilities		(135,818)		(113,910)

Other comprehensive loss deferred tax liability		(28)		(83)

Net deferred tax liabilities	$	(90,285)	$	(78,280)

As of December 31, 2018, the Company had net operating loss carry forwards of approximately $188.3 million for federal tax purposes and $0.8 million for state tax purposes. The federal net operating loss carry forwards will expire at various times from 2023 to 2037 and the state net operating loss carry forwards will expire at various times from 2019 to 2038. Federal net operating loss generated in 2018 under US tax reform has an indefinite life. The gross 2004 California net operating loss of $5.5 million expired in 2018. There is a $0.7 million valuation allowance for net operating losses in California that expire between 2019 and 2038. The Company’s ability to utilize the net operating loss and tax credit carry forwards in the future may be subject to restriction in the event of past or future ownership changes as defined in Section 382 of the Internal Revenue Code and similar state tax law. In 2017, the Company included the alternative minimum tax credit of approximately $0.4 million for federal income tax purposes as a tax receivable and will recognize this credit between 2-4 years to offset future regular tax liabilities. Management believes that no valuation allowance is required on deferred tax assets related to federal net operating loss carry forwards, as it is more likely than not that all amounts are recoverable through future taxable income. The open tax years for federal and state tax purposes are from 2015-2018 and 2014-2018, respectively.

On December 22, 2017, the 2017 Act was signed into law, making significant changes to the Internal Revenue Code. Changes include, but are not limited to, a corporate tax rate decrease from 35% to 21% effective for tax years beginning after December 31, 2017, the transition of U.S. international taxation from a worldwide tax system to a territorial system, and a one-time transition tax on the mandatory deemed repatriation of cumulative foreign earnings as of December 31, 2017. The Company calculated the impact of the 2017 Act in the 2017 year end income tax provision in accordance with management’s understanding of the 2017 Act and guidance available as of the date of the 2017 filing and as a result recorded an income tax benefit in 2017. The benefit related to the remeasurement of certain deferred tax assets and liabilities, based on the rates at which they were expected to reverse in the future, was $43.6 million.