13. Income Taxes

Components of income tax expense (benefit) consist of the following (in thousands):

	Year Ended December 31,
	2014			2013			2012
Current:
Federal	$	137,993		$	120,030		$	83,905
State		19,051			20,099			13,949
Foreign		1,252			2,164			659

Total current		158,296			142,293			98,513
Deferred
Federal		(2,945	)		(37,713	)		37,259
State		463			(9,059	)		(415	)
Foreign		(225	)		(1,055	)		182

Total deferred		(2,707	)		(47,827	)		37,026

Other non-current
Federal		27,115			7,797			573
State		2,383			1,907			114
Foreign		19			173			3

Total other		29,517			9,877			690

Total income tax expense	$	185,106		$	104,343		$	136,229

Presented below is a reconciliation of income taxes computed at the statutory federal tax rate to income tax expense as reported (in thousands):

	Year Ended December 31,
	2014			2013			2012
Federal tax provision computed at 35%	$	183,813		$	97,616		$	154,235
State tax provision, net of federal tax provision		12,865			8,320			9,149
General business credits		(12,195	)		(13,346	)		(10,980	)
Incentive stock option expense		(181	)		(304	)		(479	)
Section 199 deduction		(11,735	)		(10,861	)		(15,629	)
Nondeductible compensation expense		13,000			22,813			2,609
Nondeductible expenses		(461	)		105			(2,676	)

Total income tax expense	$	185,106		$	104,343		$	136,229

Components of the net deferred tax asset are as follows (in thousands):

	As of December 31,
	2014			2013
Deferred tax assets:
General business credits	$	2,186		$	277
Impairment losses on investments		291			318
License fees capitalized for tax purposes		61,770			75,181
Nonqualified stock options		42,697			40,808
SERP		17,478			14,059
STAP awards		86,414			84,274
Other		29,086			28,118

Total deferred tax assets		239,922			243,035
Deferred tax liabilities:
Plant and equipment principally due to differences in depreciation		(30,758	)		(32,725	)
Other		(7,854	)		(1,351	)

Net deferred tax asset before valuation allowance		201,310			208,959
Valuation allowance		(2,981	)		(2,507	)

Net deferred tax assets	$	198,329		$	206,452

Deferred tax assets are reduced by a valuation allowance when, in our judgment, it is more likely than not that a portion or all of the deferred tax assets will not be realized. In evaluating our ability to realize deferred tax assets, we consider all available positive and negative evidence. Accordingly, we consider past operating results, forecasts of earnings and taxable income, the reversal of temporary differences and any prudent and feasible tax planning strategies. Future increases in the valuation allowance would result in a corresponding charge to earnings in the period such a determination is made. Conversely, future reductions to the valuation allowance would result in the recognition of a tax benefit in the period we conclude a reduction is warranted.

We expect to utilize all of our federal general business tax credits in tax year 2014.

A reconciliation of the beginning and ending balances of unrecognized tax benefits for the years indicated is as follows (in thousands):

Unrecognized tax benefits at January 1, 2014	$	2,836
Gross increases—tax positions in prior period		28
Gross decreases—tax positions in prior period		(1,419	)
Gross increases—tax positions in the current period		—
Gross decreases—tax positions in current period		—
Settlements		—
Lapse of statute of limitations		—

Unrecognized tax benefits at December 31, 2014	$	1,445


Unrecognized tax benefits at January 1, 2013	$	1,511
Gross increases—tax positions in prior period		1,325
Gross decreases—tax positions in prior period		—
Gross increases—tax positions in the current period		—
Gross decreases—tax positions in the current period		—
Settlements		—
Lapse of statute of limitations		—

Unrecognized tax benefits at December 31, 2013	$	2,836


Unrecognized tax benefits at January 1, 2012	$	1,733
Gross increases—tax positions in prior period		146
Gross decreases—tax positions in prior period		(368	)
Gross increases—tax positions in the current period		—
Gross decreases—tax positions in the current period		—
Settlements		—
Lapse of statute of limitations		—

Unrecognized tax benefits at December 31, 2012	$	1,511

Included in unrecognized tax benefits at December 31, 2014, 2013 and 2012, is $1.0 million, $2.4 million, and $1.0 million, respectively, of tax benefits that, if recognized, would impact the effective tax rate. As of December 31, 2014 and 2013, we accrued $28,000 and $249,000, respectively, in interest expense relating to uncertain state tax positions.

We are subject to federal and state taxation in the United States and various foreign jurisdictions. Currently, our 2013, 2012, 2011 and 2010 tax years are subject to examination by the IRS and by state taxing authorities. We are unaware of any positions for which it is reasonably possible that the total amounts of unrecognized tax benefits will significantly increase or decrease within the next twelve months.