Income Taxes

3 Months Ended

Dec. 31, 2021

Income Tax Disclosure [Abstract]

Income Taxes

Income Taxes

Effective Tax Rate

The effective income tax rate was 18.9% and 1.7% during the quarters ended December 31, 2021 and 2020, respectively. The provision for income taxes during interim quarterly reporting periods is based on our estimates of the effective tax rates for the full fiscal year. The effective tax rate in any quarter can also be affected positively or negatively by adjustments that are required to be reported in the specific quarter of resolution.

The effective tax rates for the quarters ended December 31, 2021 and 2020 were both impacted favorably by the recording of excess tax benefits relating to stock awards. The impact is dependent upon grants of share-based compensation and the future stock price in relation to the fair value of awards on the grant date. The decrease in stock price for awards that vested in December 2021 resulted in a decreased net excess tax benefit for the quarter ended December 31, 2021.

The total unrecognized tax benefit for uncertain tax positions was estimated to be $11.8 million and $10.9 million at December 31, 2021 and September 30, 2021, respectively. We recognize interest expense related to unrecognized tax benefits and penalties as part of the provision for income taxes in our condensed consolidated statements of income and comprehensive income. We accrued interest of $0.5 million and $0.4 million related to unrecognized tax benefits as of December 31, 2021 and September 30, 2021, respectively.