(4) Income Taxes

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


	Year ended December 31,
	2015		2014		2013
Current tax provision (benefit):
Federal	$	3,801	$	(176)	$	1,767
State		1,035		838		343
Foreign		—		2,081		—
		4,836		2,743		2,110
Deferred tax provision (benefit):
Federal		66,430		4,697		34,728
State		5,239		371		2,738
		71,669		5,068		37,466
Provision for income taxes	$	76,505	$	7,811	$	39,576

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,
	2015		2014		2013
Computed provision (benefit) for income taxes at the statutory rate	$	68,013	$	(5,720)	$	34,486
Increase (decrease) in income taxes resulting from:
State income tax provision (benefit), net of federal income tax benefit		5,416		(107)		2,867
Non-deductible expenses		3,641		3,865		3,257
Valuation allowance changes affecting the provision for income taxes		(899)		5,981		1,430
Foreign income taxes, net of federal & state benefit		—		1,973
Other, net		334		1,819		(2,464)
Provision for income taxes	$	76,505	$	7,811	$	39,576

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 gain resulting from the early retirement of certain long term debt which reduced the amount of deferred tax assets that were 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 allowance 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 additionally recorded a $2.0 million foreign tax expense associated with Brazilian withholding tax on the sale of the Company's equity ownership in TRIP.

For the year ended December 31, 2013, the Company recorded a $1.4 million valuation allowance against certain deferred tax assets primarily associated with ExpressJet state net operating losses with a limited carry forward period. The valuation allowance was based on the Company’s assessment at December 31, 2013 of deferred tax assets that were anticipated to expire before the deferred tax assets may be utilized.

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,
	2015		2014
Deferred tax assets:
Intangible Asset	$	30,369	$	34,819
Accrued benefits		47,514		43,853
Net operating loss carryforward		82,211		152,361
AMT credit carryforward		21,391		17,590
Deferred aircraft credits		55,544		53,797
Accrued reserves and other		24,575		27,008
Total deferred tax assets		261,604		329,428
Valuation allowance		(8,126)		(9,025)
Deferred tax liabilities:
Accelerated depreciation		(902,322)		(895,405)
Total deferred tax liabilities		(902,322)		(895,405)
Net deferred tax liability	$	(648,844)	$	(575,002)

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 US 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, 2015 and 2014, the Company had federal net operating losses, net of valuation allowance, of approximately $189.0 million and $379.3 million and state net operating losses of approximately $352.2 million and $452.2 million, respectively. The estimated effective tax rate applicable to the state and federal net operating losses net of valuation allowances as of December 31, 2015 was 35.0% and 2.6%, respectively. The Company anticipates that the federal and state net operating losses will start to expire in 2026 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, 2015 and 2014, the Company also had an alternative minimum tax credit of approximately $21.4 million and $17.6 million, respectively, which does not expire.