Income Taxes	3 Months Ended
Mar. 31, 2019
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company's tax provision for interim periods is determined using an estimated annual effective tax rate, adjusted for discrete items arising in that quarter. In each quarter, the estimated annual effective tax rate is updated and a year-to-date adjustment is made to the provision. The Company's quarterly effective tax rate is subject to significant change due to the effect of discrete items arising in a given quarter. There was an income tax benefit for the quarter ended March 31, 2019, of $1,459, for an effective tax rate of (17.7) percent. The effective tax rate differed from the 21 percent federal statutory rate on pretax income, primarily due to the tax impact of vested share-based awards, the tax impact of state and federal tax credits, partially offset by state taxes and certain compensation being subject to the compensation deduction limitations applicable for public companies. Income tax expense for the quarter ended March 31, 2018, was $1,255, for an effective tax rate for the quarter of 12.3 percent. The effective tax rate differed from the 21 percent federal statutory rate on pretax income, primarily due to the tax impact of vested share-based awards, income tax credits including state income tax credits in Indiana and Kansas, partially offset by state taxes.

Income Taxes

The Company's tax provision for interim periods is determined using an estimated annual effective tax rate, adjusted for discrete items arising in that quarter. In each quarter, the estimated annual effective tax rate is updated and a year-to-date adjustment is made to the provision. The Company's quarterly effective tax rate is subject to significant change due to the effect of discrete items arising in a given quarter. There was an income tax benefit for the quarter ended March 31, 2019, of $1,459, for an effective tax rate of (17.7) percent. The effective tax rate differed from the 21 percent federal statutory rate on pretax income, primarily due to the tax impact of vested share-based awards, the tax impact of state and federal tax credits, partially offset by state taxes and certain compensation being subject to the compensation deduction limitations applicable for public companies.

Income tax expense for the quarter ended March 31, 2018, was $1,255, for an effective tax rate for the quarter of 12.3 percent. The effective tax rate differed from the 21 percent federal statutory rate on pretax income, primarily due to the tax impact of vested share-based awards, income tax credits including state income tax credits in Indiana and Kansas, partially offset by state taxes.