The Issuer, has issued long term borrowings in the form of senior notes (the "Notes"). The Notes are unsecured and unsubordinated obligations of the Issuer. The Notes are fully and unconditionally guaranteed, jointly and severally, by the Partnership, Blackstone Holdings (the "Guarantors"), and the Issuer. The guarantees are unsecured and unsubordinated obligations of the Guarantors. Transaction costs related to the issuance of the Notes have been deducted from the Note liability and are being amortized over the life of the Notes. The indentures include covenants, including limitations on the Issuer's and the Guarantors' ability to, subject to exceptions, incur indebtedness secured by liens on voting stock or profit participating equity interests of their subsidiaries or merge, consolidate or sell, transfer or lease assets. The indentures also provide for events of default and further provide that the trustee or the holders of not less than 25% in aggregate principal amount of the outstanding Notes may declare the Notes immediately due and payable upon the occurrence and during the continuance of any event of default after expiration of any applicable grace period. In the case of specified events of bankruptcy, insolvency, receivership or reorganization, the principal amount of the Notes and any accrued and unpaid interest on the Notes automatically become due and payable. All or a portion of the Notes may be redeemed at the Issuer's option in whole or in part, at any time and from time to time, prior to their stated maturity, at the make-whole redemption price set forth in the Notes. If a change of control repurchase event occurs, the holders of the Notes may require the Issuer to repurchase the Notes at a repurchase price in cash equal to 101% of the aggregate principal amount of the Notes repurchased plus any accrued and unpaid interest on the Notes repurchased to, but not including, the date of repurchase. Interest expense on the Notes was $136.7 million, $200.4 million and $145.6 million for the years ended December 31, 2018, 2017 and 2016, respectively.