The reimbursement of the HIF from our state customers may be settled as a separate payment or monthly in combination with our other premium payments. The vast majority of our state customers are settling the reimbursement through a separate payment after verification of each state's portion of our HIF, resulting in an increase in Premium and Related Receivables at December 31, 2016. During 2016, we paid the 2016 annual HIF totaling $513 million. This negatively impacted our cash flows as we have not been reimbursed from many of our state customers. Similarly, during 2015, we paid the 2015 annual HIF invoice totaling $220 million. The table below details the impact to cash flows from operations from the timing of payments from our states ($ in millions).
In February 2016, our wholly owned unrestricted subsidiary (Escrow Issuer) issued $1,400 million of 5.625% Senior Notes ($1,400 Million Notes) at par due 2021 and $1,000 million of 6.125% Senior Notes ($1,000 Million Notes) at par due 2024. We used the net proceeds of the offering, together with borrowings under the our new $1,000 million revolving credit facility and cash on hand, to fund the cash consideration for the Health Net acquisition and to pay acquisition and offering related fees and expenses. In connection with the February 2016 issuance, we entered into interest rate swap agreements for notional amounts of $600 million and $1,000 million, at floating rates of interest based on the three month LIBOR plus 4.22% and the three month LIBOR plus 4.44%, respectively. Gains and losses due to changes in the fair value of the interest rate swaps completely offset changes in the fair value of the hedged portion of the underlying debt and are recorded as an adjustment to the $1,400 Million Notes and $1,000 Million Notes.
We also have audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States), Centene Corporation’s internal control over financial reporting as of December 31, 2016, based on criteria established in Internal Control - Integrated Framework (2013) issued by the Committee of Sponsoring Organizations of the Treadway Commission (COSO), and our report dated February 20, 2017 expressed an unqualified opinion on the effectiveness of the Company’s internal control over financial reporting.
The fair value of premium and related receivables approximated their historical cost, with the exception of the risk corridor receivable associated with the Health Insurance Marketplace. The fair value of the risk corridor receivable was estimated at $9 million.
(1) In 2016, the Company purchased a controlling interest in TPG for $8 million.
During the years ended December 31, 2016, 2015 and 2014, the company recognized $5 million, $8 million and $6 million, respectively, of income from equity method investments.
The Company continuously monitors investments for other-than-temporary impairment. Certain investments have experienced a decline in fair value due to changes in credit quality, market interest rates and/or general economic conditions. The Company recognizes an impairment loss for cost and equity method investments when evidence demonstrates that it is other-than-temporarily impaired. Evidence of a loss in value that is other-than-temporary may include the absence of an ability to recover the carrying amount of the investment or the inability of the investee to sustain a level of earnings that would justify the carrying amount of the investment.
In February 2016, a wholly owned unrestricted subsidiary of the Company (Escrow Issuer) issued $1,400 million in aggregate principal amount of 5.625% Senior Notes ($1,400 Million Notes) at par due 2021 and $1,000 million in aggregate principal amount of 6.125% Senior Notes ($1,000 Million Notes) at par due 2024. In July 2016, the Company completed an exchange offer, whereby it offered to exchange all of the outstanding $1,400 Million Notes and the $1,000 Million Notes for identical securities that have been registered under the Securities Act of 1933. The Company used the net proceeds of the offering, together with borrowings under the Company's new $1,000 million revolving credit facility and cash on hand, primarily to fund the cash consideration for the Health Net acquisition, and to pay acquisition and offering related fees and expenses.
to uncertain positions of $1 million. The Company had $5 million and $1 million of accrued interest and penalties for uncertain tax positions as of December 31, 2016 and 2015, respectively.
The Company maintains an employee stock purchase plan and issued 118,293 shares, 86,819 shares, and 76,088 shares in 2016, 2015 and 2014, respectively.