(4) Income Taxes

The provision for income taxes includes the following components (in thousands):


	Year ended December 31,
	2016		2015		2014
Current tax provision (benefit):
Federal	$	(3,801)	$	3,801	$	(176)
State		111		1,035		838
Foreign				—		2,081
		(3,690)		4,836		2,743
Deferred tax provision (benefit):
Federal		(77,430)		66,430		4,697
State		(6,106)		5,239		371
		(83,536)		71,669		5,068
Provision for income taxes	$	(87,226)	$	76,505	$	7,811

The following is a reconciliation between the statutory federal income tax rate of 35% and the effective rate which is derived by dividing the provision for income taxes by income (loss) before for income taxes (in thousands):


	Year ended December 31,
	2016		2015		2014
Computed provision (benefit) for income taxes at the statutory rate	$	(87,084)	$	68,013	$	(5,720)
Increase (decrease) in income taxes resulting from:
State income tax provision (benefit), net of federal income tax benefit		(5,768)		5,416		(107)
Non-deductible expenses		3,552		3,641		3,865
Valuation allowance changes affecting the provision for income taxes		751		(899)		5,981
Foreign income taxes, net of federal & state benefit		—		—		1,973
Other, net		1,323		334		1,819
Provision for income taxes	$	(87,226)	$	76,505	$	7,811

For the year ended December 31, 2016, the Company recorded a $0.8 million valuation allowance against certain deferred tax assets primarily associated with ExpressJet state net operating losses with a limited carry forward period. The release of the valuation allowance was based on changes in state tax laws and the Company's income tax projections which reduced the amount of deferred tax assets that are anticipated to expire before the deferred tax assets may be utilized.

For the year ended December 31, 2015, the Company released a $0.9 million valuation allowance against certain deferred tax assets primarily associated with ExpressJet state net operating losses with a limited carry forward period. The release of the valuation allowance was based on the Company's other income related to early retirement of certain long term debt which reduced the amount of deferred tax assets that are anticipated to expire before the deferred tax assets may be utilized.

For the year ended December 31, 2014, the Company recorded a $6.0 million valuation allowance against certain deferred tax assets primarily associated with ExpressJet state net operating losses with a limited carry forward period. The valuation was based on the Company's assessment of deferred tax assets that are anticipated to expire before the deferred tax assets may be utilized. The Company also recorded a $2.0 million foreign tax expense associated with Brazilian withholding tax on the sale of the Company's equity interest in TRIP.

The significant components of the Company’s net deferred tax assets and liabilities as of December 31, 2015 and 2014 are as follows (in thousands):


	As of December 31,
	2016		2015
Deferred tax assets:
Intangible asset	$	4,983	$	30,369
Accrued benefits		48,482		47,514
Net operating loss carryforward		286,389		82,211
AMT credit carryforward		17,589		21,391
Deferred aircraft credits		60,415		55,544
Accrued reserves and other		47,906		24,575
Total deferred tax assets		465,764		261,604
Valuation allowance		(8,877)		(8,126)
Deferred tax liabilities:
Accelerated depreciation		(1,022,291)		(902,322)
Total deferred tax liabilities		(1,022,291)		(902,322)
Net deferred tax liability	$	(565,404)	$	(648,844)

The Company’s deferred tax liabilities were primarily generated through accelerated depreciation, combined with shorter depreciable tax lives, allowed under the IRS tax code for purchased aircraft and support equipment compared to the Company’s U.S. Generally Accepted Accounting Principles ("GAAP") depreciation policy for such assets using the straight-line method (see Note 1 Nature of Operations and Summary of Significant Accounting Policies).

The Company's valuation allowance is related to certain deferred tax assets with a limited carry forward period. The Company does not anticipate utilizing these deferred tax assets prior to the lapse of the carry forward period.

At December 31, 2016 and 2015, the Company had federal net operating losses of approximately $763.9 million and $189.0 million and state net operating losses of approximately $469.2 million and $352.2 million, respectively. The estimated effective tax rate applicable to the state and federal net operating losses as of December 31, 2016 was 35.0% and 2.6%, respectively. The Company anticipates that the federal and state net operating losses will start to expire in 2027 and 2017, respectively. The Company has recorded a valuation allowance for state net operating losses the Company anticipates will expire before the benefit will be realized due to the limited carry forward periods. As of December 31, 2016 and 2015, the Company also had an alternative minimum tax credit of approximately $17.6 million and $21.4 million, respectively, which does not expire.