LONG-TERM DEBT

Long-term debt

Long-term debt is comprised of the following:



	As of June 30, 2018			As of June 30, 2017
Total debt
Senior Notes 2026	$	850,000		$	850,000
Senior Notes 2023	800,000			800,000
Term Loan B	997,500			772,120
Revolver	—			175,000
Total principal payments due	2,647,500			2,597,120

Premium on Senior Notes 2026	6,018			6,597
Debt issuance costs	(32,995		)	(33,900		)
Total amount outstanding	2,620,523			2,569,817

Less:
Current portion of long-term debt
Term Loan B	10,000			7,760
Revolver	—			175,000
Total current portion of long-term debt	10,000			182,760

Non-current portion of long-term debt	$	2,610,523		$	2,387,057

Senior Unsecured Fixed Rate Notes

Senior Notes 2026

On May 31, 2016, we issued $600 million in aggregate principal amount of 5.875% Senior Notes due 2026 (Senior Notes 2026) in an unregistered offering to qualified institutional buyers pursuant to Rule 144A under the Securities Act of 1933, as amended (Securities Act), and to certain persons in offshore transactions pursuant to Regulation S under the Securities Act. Senior Notes 2026 bear interest at a rate of 5.875% per annum, payable semi-annually in arrears on June 1 and December 1, commencing on December 1, 2016. Senior Notes 2026 will mature on June 1, 2026, unless earlier redeemed, in accordance with their terms, or repurchased.

On December 20, 2016, we issued an additional $250 million in aggregate principal amount by reopening our Senior Notes 2026 at an issue price of 102.75%. The additional notes have identical terms, are fungible with and are a part of a single series with the previously issued $600 million aggregate principal amount of Senior Notes 2026. The outstanding aggregate principal amount of Senior Notes 2026, after taking into consideration the additional issuance, is $850 million.

For the year ended June 30, 2018, we recorded interest expense of $49.9 million, relating to Senior Notes 2026 (year ended June 30, 2017 and 2016—$43.1 million and $2.9 million, respectively).

Senior Notes 2023

On January 15, 2015, we issued $800 million in aggregate principal amount of 5.625% Senior Notes due 2023 (Senior Notes 2023 and together with Senior Notes 2026, Senior Notes) in an unregistered offering to qualified institutional buyers pursuant to Rule 144A under the Securities Act, and to certain persons in offshore transactions pursuant to Regulation S under the Securities Act. Senior Notes 2023 bear interest at a rate of 5.625% per annum, payable semi-annually in arrears on January 15 and July 15, commencing on July 15, 2015. Senior Notes 2023 will mature on January 15, 2023, unless earlier redeemed, in accordance with their terms, or repurchased.

For the year ended June 30, 2018, we recorded interest expense of $45.0 million, relating to Senior Notes 2023 (year ended June 30, 2017 and 2016—$45.0 million, respectively).

Term Loan B

On May 30, 2018, we refinanced our existing term loan facility (Term Loan B), by entering into a new $1 billion term loan facility, whereby we borrowed $1 billion on that day and repaid in full the loans under our prior $800 million term loan credit facility originally entered into on January 16, 2014. Borrowings under Term Loan B are secured by a first charge over substantially all of our assets on a pari passu basis with the Revolver (defined below).

Term Loan B has a seven year term and repayments made under Term Loan B are equal to 0.25% of the principal amount in equal quarterly installments for the life of Term Loan B, with the remainder due at maturity. Borrowings under Term Loan B currently bear a floating rate of interest equal to 1.75% plus LIBOR. As of June 30, 2018, the outstanding balance on the Term Loan B bears an interest rate of approximately 3.73%.

For the year ended June 30, 2018, we recorded interest expense of $27.9 million, relating to Term Loan B (year ended June 30, 2017 and 2016—$24.8 million and $25.9 million, respectively).

Revolver

We currently have a $450 million committed revolving credit facility (the Revolver) with a maturity date of May 5, 2022. Borrowings under the Revolver are secured by a first charge over substantially all of our assets, on a pari passu basis with Term Loan B. The Revolver has no fixed repayment date prior to the end of the term. Borrowings under the Revolver bear interest per annum at a floating rate of LIBOR plus a fixed margin dependent on our consolidated net leverage ratio ranging from 1.25% to 1.75%.

During the year ended June 30, 2018, we drew down $200 million, from the Revolver partially to finance acquisitions (year ended June 30, 2017 and 2016—$225 million and nil, respectively).

During the year ended June 30, 2018, we repaid $375 million (year ended June 30, 2017 and 2016—$50 million and nil, respectively). As of June 30, 2018 we have no outstanding balance on the Revolver.

For the year ended June 30, 2018, we recorded interest expense of $9.0 million, relating to amounts drawn on the Revolver (year ended June 30, 2017 and 2016—$2.6 million and nil, respectively).

Debt Issuance Costs and Premium on Senior Notes

Debt issuance costs relate primarily to costs incurred for the purpose of obtaining our credit facilities and issuing our Senior Notes and are being amortized over the respective terms of the Senior Notes and Term Loan B using the effective interest method and the Revolver using the straight-line method.

In connection with the recent refinancing and amendment of Term Loan B, we incurred new debt issuance costs of approximately $4.7 million, of which approximately $4.4 million has been paid as of June 30, 2018. Furthermore, during the year ended June 30, 2018, we wrote off $0.2 million of unamortized debt issuance costs relating to the portion of Term Loan B that was not recommitted by certain lenders under the new terms and were therefore considered extinguished. This amount has been written off to "Interest and other related expense, net" on the Consolidated Statements of Income.

The premium on Senior Notes 2026 represents the excess of the proceeds received over the face value of Senior Notes 2026. This premium is amortized as a reduction to interest expense over the term of Senior Notes 2026 using the effective interest method.