as the result of recent third-party investor’s transactions in these securities. The fair value of our investment was not readily determinable; thus, we determined the fair value utilizing a combination of quoted price inputs for the equity in our investment (Level 2) and certain management assumptions pertaining to investment value (Level 3).
Income Tax Expense
Our income tax expense was $88 million and $162 million for the three and six months ended June 30, 2020, respectively, compared to $115 million and $230 million for the three and six months ended June 30, 2019, respectively. Our effective income tax rate was 22.2% and 19.5% for the three and six months ended June 30, 2020, respectively, compared to 23.3% and 24.0% for the three and six months ended June 30, 2019, respectively.
The decrease in our income tax expense and effective income tax rate when comparing the three and six months ended June 30, 2020 with the prior year periods are driven by (i) a decrease in pre-tax income in 2020, which increased the effective tax rate impact of our federal tax credits, and to a lesser extent; (ii) a $52 million non-cash impairment charge recognized during the first quarter of 2019 that was not deductible for tax purposes and (iii) excess tax benefits associated with equity-based compensation, which were slightly higher in 2020 than in the prior year.
On March 27, 2020, the CARES Act was enacted in response to the COVID-19 pandemic. The CARES Act contains numerous income tax provisions, none of which directly affected our income tax expense for the three and six months ended June 30, 2020 or are expected to have a material impact on our income tax expense in future reporting periods. The Company is evaluating the impact of the CARES Act and expects to benefit from the deferral of certain payroll taxes through the end of calendar year 2020.
Liquidity and Capital Resources
The Company consistently generates cash flow from operations that meets and exceeds our working capital needs, payment of our dividends and investment in the business through capital expenditures and acquisitions. We continually monitor our actual and forecasted cash flows, our liquidity and our capital resources, enabling us to plan for our present needs and fund unbudgeted business requirements that may arise during the year, including the anticipated impact from COVID-19. Additionally, the Company is taking numerous actions to manage costs and capital spending without compromising long-term strategic priorities. This includes route optimization initiatives, reducing overtime hours, limiting hiring and optimizing our workforce through improved retention and reduced turnover, reducing non-essential selling, general and administrative expenses, reducing incentive compensation costs and lowering capital expenditures to a level that is consistent with anticipated volume changes. Additionally, as a result of the CARES Act discussed above in Income Tax Expense, we are currently benefiting from the deferral of certain payroll taxes, which will continue through the end of calendar year 2020, favorably impacting our net cash provided by operating activities. The Company believes that its investment grade credit ratings, large value of unencumbered assets and modest leverage enable it to obtain adequate financing to meet its ongoing capital, operating and other liquidity requirements, despite the disruptions and challenges presented by the COVID-19 pandemic. The long-term impacts from COVID-19 on our business, financial condition and operating results cannot be predicted with reasonable certainty at this time.
As discussed in Note 3 to the Condensed Consolidated Financial Statements, as of June 30, 2020, we had $3.0 billion of senior notes due 2024, 2026, 2029 and 2039 with a special mandatory redemption feature (the “SMR Notes”). The SMR Notes were issued in May 2019 with the intention of paying a portion of the consideration related to our pending acquisition of Advanced Disposal. The Advanced Disposal acquisition, and the revised acquisition terms announced on June 24, 2020, are discussed further in Note 8 to the Condensed Consolidated Financial Statements. Pursuant to the terms of the SMR Notes, we were required to redeem all of such outstanding notes equal to 101% of the aggregate principal amounts of such notes, plus accrued but unpaid interest, as a result of the acquisition not being completed by July 14, 2020. Accordingly, as of June 30, 2020, we have classified the SMR Notes, net of $22 million of related unamortized discounts and deferred issuance costs, as current obligations. As reported in Note 14 to the Condensed Consolidated Financial Statements, on July 20, 2020, we fulfilled our redemption obligations with respect to the SMR notes using available cash on hand and, to a lesser extent, commercial paper borrowings. The cash paid included the $3.0 billion principal amount of debt redeemed, $30 million of related premiums and $8 million of accrued interest. When we announced the revised acquisition terms on