Income Taxes	6 Months Ended
Jun. 30, 2019
Income Taxes [Abstract]
Income Taxes	12. Income Taxes The Company filed for a change in accounting method under the Internal Revenue Service tangible property regulations, or TPR, effective in 2014. Under the change in accounting method, the Company is permitted to deduct the costs of certain asset improvements that were previously being capitalized and depreciated for tax purposes as an expense on its income tax return. This ongoing deduction results in a reduction in the effective income tax rate, a net reduction in income tax expense, and a reduction in the amount of income taxes currently payable. It also results in increases to deferred tax liabilities and regulatory assets representing the appropriate book and tax basis difference on capital additions. The Company’s effective tax rate was 15.2% and 7.6% for the three months ended June 30, 2019 and 2018, respectively, and 17.3% and 16.2% for the six months ended June 30, 2019 and 2018, respectively. The effective tax rate is higher for the three and six months ended June 30, 2019 compared to 2018, primarily due to a lower level of eligible asset improvements that were placed into service and higher state income taxes. The effective tax rate will vary depending on the level of eligible asset improvements expensed for tax purposes under TPR each period.

12. Income Taxes

The Company filed for a change in accounting method under the Internal Revenue Service tangible property regulations, or TPR, effective in 2014. Under the change in accounting method, the Company is permitted to deduct the costs of certain asset improvements that were previously being capitalized and depreciated for tax purposes as an expense on its income tax return. This ongoing deduction results in a reduction in the effective income tax rate, a net reduction in income tax expense, and a reduction in the amount of income taxes currently payable. It also results in increases to deferred tax liabilities and regulatory assets representing the appropriate book and tax basis difference on capital additions.

The Company’s effective tax rate was 15.2% and 7.6% for the three months ended June 30, 2019 and 2018, respectively, and 17.3% and 16.2% for the six months ended June 30, 2019 and 2018, respectively. The effective tax rate is higher for the three and six months ended June 30, 2019 compared to 2018, primarily due to a lower level of eligible asset improvements that were placed into service and higher state income taxes. The effective tax rate will vary depending on the level of eligible asset improvements expensed for tax purposes under TPR each period.