Income Taxes

The following table compares our income tax (benefit) expense and effective tax rates for the three and six months ended September 30, 2018 and 2017:



	Three months ended						Six months ended
	September 30,						September 30,
(Dollars in thousands)	2018			2017			2018			2017
Income tax expense	$	53		$	105		$	4		$	183
Effective tax rate	(1.4		)%	(3.3		)%	(0.1		)%	(3.0		)%

For the three and six months ended September 30, 2018, the effective tax rate was different than the statutory rate due primarily to the recognition of net operating losses as deferred tax assets, which were offset by increases in the valuation allowance, an adjustment to true-up uncertain tax positions, certain foreign and state tax effects, and other U.S. permanent book to tax differences.

For the three and six months ended September 30, 2017, the effective tax rate was different than the statutory rate due primarily to the recognition of net operating losses as deferred tax assets, which were offset by increases in the valuation allowance, certain foreign and state tax effects, and other U.S. permanent book to tax differences.

We have recorded a valuation allowance offsetting substantially all of our deferred tax assets. The ultimate realization of deferred tax assets depends on the generation of future taxable income during the periods in which those temporary differences are deductible. Because of our losses in prior periods, management believes that it is more-likely-than-not that we will not realize the benefits of these deductible differences.

On December 22, 2017, the staff of the Securities and Exchange Commission issued Staff Accounting Bulletin ("SAB") No. 118, which provides guidance on accounting for the tax effects of the Tax Act. SAB No. 118 allows registrants to record provisional amounts for a period up to one year from the date of enactment of the Tax Act when the registrant does not have the necessary information available, prepared, or analyzed (including computations) in reasonable detail to complete the accounting for certain income tax effects of the Tax Act. It is uncertain if and to what extent various states will enact legislation to conform to the Tax Act. Because legislative guidance and accounting interpretations are expected in the future, we consider the accounting of the deferred tax remeasurement including the ability to offset indefinite lived deferred tax liabilities with certain deferred tax assets to be incomplete and therefore only consider amounts related to these items to be reasonably estimated as of March 31, 2018 and September 30, 2018. We expect to refine and complete the accounting for the Tax Act during fiscal 2019 as we obtain, prepare and analyze additional information and as additional legislative, regulatory and accounting guidance and interpretations become available.