Income Taxes

The Company adjusts its effective tax rate each quarter to be consistent with the estimated annual effective tax rate. The Company also records the tax effect of unusual or infrequently occurring discrete items.

The provision for income taxes is shown in the tables below:



	Three Months Ended June 30
	2018		2017
Income tax expense	$	3,527	$	10,852



	Six Months Ended June 30
	2018		2017
Income tax expense	$	2,540	$	10,857

The income tax expense decreased $7.3 million to $3.5 million for the three months ended June 30, 2018 as compared to the three months ended June 30, 2017 mostly due to the federal income tax rate reduction from 35% to 21%, effective January 1, 2018, and a decrease in operating income.

The income tax expense decreased $8.3 million to $2.5 million in the first six months of 2018, as compared to $10.9 million in the first six months of 2017. The decrease was mainly due to the federal income tax rate reduction from 35% to 21%, effective January 1, 2018, and a decrease in operating income.

The Company's 2018 effective tax rate, before discrete items, is estimated to be in the range from 23% to 25%.

For year ended December 31, 2017, the Company recorded a provisional re-measurement of its deferred tax balances (related mostly to timing differences for plant-related items) which was offset by a change from a net deferred income tax regulatory asset to a net regulatory liability. The Company is continuing to work with state regulators to finalize the customer net refund of $108.0 million to ensure compliance with federal normalization rules.

The final transition impacts of the Tax Cuts and Jobs Act (TCJA) may differ from the recorded amounts, possibly materially, due to, among other things, regulatory decisions that could differ from the Company’s determination of how the impacts of the TCJA are allocated between customers and shareholders. In addition, while the Company was able to make reasonable estimates of the impact of the reduction in federal tax rate and the elimination of bonus depreciation due to the enactment of the TCJA; the Company has not completed analysis for areas of the TCJA around Internal Revenue Code Section 162(m), full expensing of fixed assets, and other asset related items of the TCJA. Changes in interpretations, guidance on legislative intent, and any changes in accounting standards for income taxes in response to the TCJA could impact the recorded amounts. The Company will finalize and record any adjustments related to the TCJA within the one year measurement period provided under Staff Accounting Bulletin No. 118. The balances relating to TCJA impact continue to be provisional as of June 30, 2018.

The Company had unrecognized tax benefits of approximately $11.5 million and $10.2 million as of June 30, 2018 and 2017, respectively. Included in the balance of unrecognized tax benefits as of June 30, 2018 and 2017 are approximately $2.2 million and $2.3 million, respectively, of tax benefits that, if recognized, would result in an adjustment to the Company’s effective tax rate. The Company does not expect its unrecognized tax benefits to change significantly within the next 12 months.