(5) INCOME TAXES

Income tax (benefit) expense was as follows (in thousands):

		Three Months Ended September 30,						Nine Months Ended September 30,
		2015			2014			2015			2014
Income tax (benefit) expense	$	(134,781	)	$	93,522		$	(174,390	)	$	230,455
Effective tax rate		30.9	%		39.0	%		30.8	%		39.7	%

We compute our quarterly taxes under the effective tax rate method based on applying an anticipated annual effective rate to our year-to-date income, except for discrete items. The three months and the nine months ended September 30, 2015 includes tax expense of $28.5 million related to an increase in our valuation allowance for federal net operating loss carryforwards that we do not believe are realizable. The three months ended September 30, 2015 includes $8.5 million of income tax expense and the nine months ended September 30, 2015 includes $19.8 million income tax expense related to increases in our valuation allowances for state net operating loss and credit carryforwards that we do not believe are realizable. Income taxes for discrete items are computed and recorded in the period that the specific transaction occurs. For third quarter and the nine months ended September 30, 2015 and 2014, our overall effective tax rate was different than the federal statutory rate of 35% due primarily to state income taxes, valuation allowances and other permanent differences. The three months ended September 30, 2015 also includes an income tax benefit of $2.6 million and the nine months ended September 30, 2015 includes an income tax benefit of $3.5 million adjusting our valuation allowance for our deferred tax asset related to future deferred compensation plan distributions of our senior executives.