Note 4 - Income Taxes

The income tax (expense) benefit recorded for the three months ended March 31, 2017, and 2016, differs from the amounts that would be provided by applying the statutory United States federal income tax rate to income or loss before income taxes primarily due to the effect of state income taxes, changes in valuation allowances, excess tax benefits and deficiencies from share-based payment awards, and accumulated impacts of other smaller permanent differences. The quarterly rate can also be affected by the proportional impacts of forecasted net income or loss as of each period end presented.

The provision for income taxes for the three months ended March 31, 2017, and 2016, consisted of the following:



	For the Three Months Ended March 31,
	2017			2016
	(in thousands)
Current portion of income tax (expense) benefit:
Federal	$	(7,439	)	$	—
State	(3,842		)	(164		)
Deferred portion of income tax (expense) benefit	(33,225		)	195,039
Income tax (expense) benefit	$	(44,506	)	$	194,875
Effective tax rate	37.4		%	35.9		%

On a year-to-date basis, a change in the Company’s effective tax rate between reported periods will generally reflect differences in its estimated highest marginal state tax rate due to changes in the composition of income or loss from Company activities among multiple state tax jurisdictions. Cumulative effects of state tax rate changes are reflected in the period that legislation is enacted. As a result of adopting ASU 2016-09, excess tax benefits and deficiencies from share-based payment awards are expected to impact the Company’s effective tax rate between periods. Please refer to Note 2 - Basis of Presentation, Significant Accounting Policies, and Recently Issued Accounting Standards.

The change in the current portion of income tax expense relates to the effect of anticipated utilization of carryover net operating losses, deferred expenses, and carryover tax credits. The Company is generally no longer subject to United States federal or state income tax examinations by tax authorities for years before 2013, with the exception of its 2003 tax year.