unsecured revolving credit facility matured. As of September 30, 2020, the aggregate capacity of our committed unsecured revolving credit facility was approximately $6.0 billion. Lenders hold revolving commitments totaling approximately $5.5 billion that mature on May 5, 2023, commitments totaling $245.0 million that mature on May 5, 2022 and commitments totaling $5.0 million that mature on May 5, 2021.
As of September 30, 2020, borrowings under our committed unsecured revolving credit facility will generally bear interest at either (a) LIBOR plus a margin of 1.05% per year or (b) an alternative base rate plus a margin of 0.05% per year, subject, in each case, to increases or decreases based on declines in the credit ratings for our debt. We are required to pay a facility fee of 0.20% per year (also subject to increases or decreases based on declines in the credit ratings for our debt) in respect of total commitments under our unsecured revolving credit facility. Borrowings under our committed unsecured revolving credit facility are used to finance our working capital needs in the ordinary course of business and for other general corporate purposes.
Secured debt financing
In June 2020, we entered into an amendment to our secured warehouse facility to extend the final maturity to June 2021. The facility will continue to bear a floating interest rate of LIBOR plus 2.00%. As part of the amendment, the credit facility was converted to full recourse against us and excess cash collateral was released. The outstanding balance on our secured warehouse facility was $100.4 million and $128.5 million as of September 30, 2020 and December 31, 2019, respectively.
As of September 30, 2020, the outstanding balance on our secured debt financings, including our secured warehouse facility and our export credit financing, was $315.8 million and we had pledged 12 aircraft as collateral with a net book value of $636.6 million. As of December 31, 2019, the outstanding balance on our secured debt financings, including our secured warehouse facility and our export credit financing, was $460.4 million and we had pledged 15 aircraft as collateral with a net book value of $890.7 million.
Preferred equity
On March 5, 2019, we issued 10,000,000 shares of 6.150% Fixed-to-Floating Non-Cumulative Perpetual Preferred Stock, Series A (the “Series A Preferred Stock”), $0.01 par value, with a liquidation preference of $25.00 per share. We will pay dividends on the Series A Preferred Stock only when, as and if declared by the board of directors. Dividends will accrue, on a non-cumulative basis, on the stated amount of $25.00 per share at a rate per annum equal to: (i) 6.150% during the first five years and payable quarterly in arrears beginning on June 15, 2019, and (ii) three-month LIBOR plus a spread of 3.650% per annum from March 15, 2024, reset quarterly and payable quarterly in arrears beginning on June 15, 2024.
We may redeem shares of the Series A Preferred Stock at our option, in whole or in part, from time to time, on or after March 15, 2024, for cash at a redemption price equal to $25.00 per share, plus any declared and unpaid dividends to, but excluding, the redemption date, without accumulation of any undeclared dividends. We may also redeem shares of the Series A Preferred Stock at our option under certain other limited conditions.
We paid a cash dividend of $0.384375 per share on our outstanding Series A Preferred Stock on each of March 15, 2020, June 15, 2020 and September 15, 2020, and our board of directors has approved a cash dividend of $0.384375 per share on our outstanding Series A Preferred Stock to be paid on December 15, 2020.
Potential Impact of LIBOR Transition
As of September 30, 2020, we had approximately $1.3 billion of floating rate debt outstanding that used LIBOR as the applicable reference rate to calculate the interest on such debt. Additionally, our Series A Preferred Stock will in the future accrue dividends at a floating rate determined by reference to LIBOR, if available. The Chief Executive of the U.K. Financial Conduct Authority (the “FCA”), which regulates LIBOR, has announced that the FCA will no longer persuade or compel banks to submit rates for the calculation of LIBOR after 2021. That announcement indicates that the continuation of LIBOR on the current basis cannot and will not be guaranteed after 2021. Moreover, it is possible that LIBOR will be discontinued or modified prior to 2021. The U.S. Federal Reserve and the Bank of England have begun publishing a Secured Overnight Funding Rate and a reformed Sterling Overnight Index Average, respectively, which are currently intended to serve as alternative reference rates to LIBOR. At this time, however, it is not possible to predict the