Long-Term Debt | Long-Term Debt A summary of our debt as of March 31, 2023 and December 31, 2022 is as follows: March 31, 2023 December 31, 2022 Principal Amount Carrying Value Fair Value Principal Amount Carrying Value Fair Value Senior unsecured notes $ 27,250 $ 27,159 $ 23,638 $ 26,650 $ 26,567 $ 22,426 Senior secured notes and debentures (a) 55,873 56,230 47,636 56,841 57,213 46,905 Credit facilities (b) 14,640 14,583 14,267 13,877 13,823 13,467 $ 97,763 $ 97,972 $ 85,541 $ 97,368 $ 97,603 $ 82,798 (a) Includes the Company's £625 million fixed-rate British pound sterling denominated notes (the “Sterling Notes”) (remeasured at $771 million and $755 million as of March 31, 2023 and December 31, 2022, respectively, using the exchange rate at the respective dates) and the Company's £650 million aggregate principal amount of Sterling Notes (remeasured at $802 million and $786 million as of March 31, 2023 and December 31, 2022, respectively, using the exchange rate at the respective dates). (b) The Company has availability under the Charter Communications Operating, LLC ("Charter Operating") credit facilities of approximately $3.3 billion as of March 31, 2023. The estimated fair value of the Company’s senior unsecured and secured notes and debentures as of March 31, 2023 and December 31, 2022 is based on quoted market prices in active markets and is classified within Level 1 of the valuation hierarchy, while the estimated fair value of the Company’s credit facilities is based on quoted market prices in inactive markets and is classified within Level 2. In February 2023, CCO Holdings and CCO Holdings Capital Corp. jointly issued $1.1 billion of 7.375% senior unsecured notes due March 2031 at par. The net proceeds were used for general corporate purposes, including repaying certain indebtedness, distributions to the Company's parent companies to fund buybacks of Charter Class A common stock and Charter Holdings common units and to pay related fees and expenses. In February 2023, Charter Operating entered into an amendment to its credit agreement to replace London Interbank Offering Rate ("LIBOR") as the benchmark rate applicable to the Term B loans with Secured Overnight Financing Rate ("SOFR") and in March 2023, Charter Operating entered into another amendment to its credit agreement to incur a new Term B-3 loan with an aggregate principal amount of $750 million maturing in 2030 concurrently with the cancelation of certain of Charter |