Write-off of unamortized debt issuance costs

  
Revolving Credit Facility has a variable interest rate on outstanding borrowings based on LIBOR, plus a spread based upon the Company's credit rating, which may vary between 1.125% and 2.000%. As of December 31, 2021, the interest rate spread on drawn amounts was 1.375% based on the Company's current credit rating. The revolving credit facility also has a commitment fee rate on the unutilized balance based on the Company’s credit rating. The commitment fee rate as of December 31, 2021 was 0.200% and may vary between 0.125% and 0.300%.   
Term Loan - In August 2021, the Company entered into a $650 million 3-year delayed draw term loan (the “Term Loan”) to finance a portion of the purchase price for Alion. The Term Loan must be repaid prior to or at maturity, which is 36 months from the date of the initial draw. The Term Loan has a variable interest rate on outstanding borrowings based on LIBOR, plus a spread based upon the Company's credit rating, which may vary between 1.125% and 2.000%. As of December 31, 2021, the annual interest rate spread was 1.375% based on the Company's current credit rating, and the outstanding balance was $625 million.  
As of December 31, 2021, the Company had $15 million in issued but undrawn letters of credit and $1,485 million unutilized under the Revolving Credit Facility. The Company had unamortized debt issuance costs associated with its credit facilities of $13 million and $5 million as of December 31, 2021 and 2020, respectively.   
The Revolving Credit Facility and the Term Loan contain customary affirmative and negative covenants, as well as a financial covenant based on a maximum total leverage ratio. Each of the Company's existing and future material wholly owned domestic subsidiaries, except those that are specifically designated as unrestricted subsidiaries, are and will be guarantors under the Revolving Credit Facility and the Term Loan. See Note 19: Subsidiary Guarantors.  
In 2019, the Company established an unsecured commercial paper note program, under which the Company may issue up to $1 billion of unsecured commercial paper notes. As of December 31, 2021, the Company had no outstanding debt under the commercial paper program.   
Senior Notes - In August 2021, the Company issued $400 million aggregate principal amount of callable unregistered 0.670% senior notes due 2023 and $600 million aggregate principal amount of unregistered 2.043% senior notes due 2028, both with registration rights. The net proceeds were used to fund a portion of the purchase price for the acquisition of Alion. Interest on these senior notes is payable semiannually.  
In 2020, the Company issued $500 million aggregate principal amount of 3.844% senior notes due 2025 and $500 million aggregate principal amount of 4.200% senior notes due 2030. The Company also has outstanding $600 million aggregate principal amount of 3.483% senior notes due December 2027. The net proceeds of these senior notes were intended to be used for general corporate purposes, including debt repayments and working capital. Interest on these senior notes is payable semiannually.   
In 2020, the Company redeemed $600 million aggregate principal amount of 5.000% senior notes due 2025 in accordance with the terms of the indenture governing the notes.  
The terms of the Company's senior notes limit the Company’s ability and the ability of certain of its subsidiaries to create liens, enter into sale and leaseback transactions, sell assets, and effect consolidations or mergers. The Company had unamortized debt issuance costs associated with the senior notes of $19 million and $14 million as of December 31, 2021 and 2020, respectively.   
Early Extinguishment of Debt - Details of the loss on early extinguishment of debt related to the Company's redemption of senior notes, which was included in interest expense, were as follows:

|  |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
|  |  |  |  |  |  |  |  |  |
|  |  | Year Ended |
| ($ in millions) |  | December 31, 2020 |
| Redemption and tender premiums and fees |  | $ | 15  |  |
| Write-off of unamortized debt issuance costs |  | 6  |  |
| Total loss on early extinguishment of debt |  | $ | 21  |  |

  
Mississippi Economic Development Revenue Bonds - As of each of December 31, 2021 and 2020, the Company had $84 million outstanding under Industrial Revenue Bonds issued by the Mississippi Business Finance Corporation. These bonds accrue interest at a fixed rate of 7.81% per annum (payable semi-annually) and mature in 2024.89
