Debt

A summary of short-term and long-term debt outstanding is as follows:



(in millions)	September 30, 2018		December 31, 2017
2.5% Senior Notes, due 2018 ¹	$	—	$	399
3.3% Senior Notes, due 2020 ²	698		697
4.0% Senior Notes, due 2025 ³	692		692
4.4% Senior Notes, due 2026 ⁴	892		892
2.95% Senior Notes, due 2027 ⁵	493		493
6.55% Senior Notes, due 2037 ⁶	396		396
4.5% Senior Notes, due 2048 ⁷	490		—
Total debt	3,661		3,569
Less: short-term debt including current maturities	—		399
Long-term debt	$	3,661	$	3,170


¹	We made a $400 million early repayment of our 2.5% senior notes in June of 2018.


²	Interest payments are due semiannually on February 14 and August 14, and as of September 30, 2018, the unamortized debt discount and issuance costs total $2 million.


³	Interest payments are due semiannually on June 15 and December 15, and as of September 30, 2018, the unamortized debt discount and issuance costs total $8 million.


⁴	Interest payments are due semiannually on February 15 and August 15, and as of September 30, 2018, the unamortized debt discount and issuance costs total $8 million.


⁵	Interest payments are due semiannually on January 22 and July 22, and as of September 30, 2018, the unamortized debt discount and issuance costs total $7 million.


⁶	Interest payments are due semiannually on May 15 and November 15, and as of September 30, 2018, the unamortized debt discount and issuance costs total $4 million.


⁷	Interest payments are due semiannually on May 15 and November 15, beginning on November 15, 2018, and as of September 30, 2018, the unamortized debt discount and issuance costs total $10 million.

The fair value of our total debt borrowings was $3.8 billion as of September 30, 2018 and December 31, 2017, and was estimated based on quoted market prices.

On May 17, 2018, we issued $500 million of 4.5% notes due in 2048. The notes are fully and unconditionally guaranteed by our wholly-owned subsidiary, Standard & Poor's Financial Services LLC. In June of 2018, we used the net proceeds to fund the redemption price of the $400 million outstanding principal amount of our 2.5% senior notes due in August of 2018, and intend to use the balance for general corporate purposes.

We have the ability to borrow a total of $1.2 billion through our commercial paper program, which is supported by our revolving$1.2 billion five-year credit agreement (our "credit facility") that we entered into on June 30, 2017. This credit facility will terminate on June 30, 2022. As of September 30, 2018 and December 31, 2017, there were no commercial paper borrowings outstanding.

Depending on our corporate credit rating, we pay a commitment fee of 8 to 17.5 basis points for our credit facility, whether or not amounts have been borrowed. We currently pay a commitment fee of 10 basis points. The interest rate on borrowings under our credit facility is, at our option, calculated using rates that are primarily based on either the prevailing London Inter-Bank Offer Rate, the prime rate determined by the administrative agent or the Federal Funds Rate. For certain borrowings under this credit facility, there is also a spread based on our corporate credit rating.

Our credit facility contains certain covenants. The only financial covenant requires that our indebtedness to cash flow ratio, as defined in our credit facility, is not greater than 4 to 1, and this covenant level has never been exceeded.