Debt

The following table presents debt balances as of June 30, 2018, and December 31, 2017.



	June 30, 2018		December 31, 2017
$545.0 million Senior Secured Term Loan B (“Senior Secured Term Loan”) bearing interest at the greater of 0.75% or one-month LIBOR (2.09% at June 30, 2018), plus an applicable margin of 3.75% at June 30, 2018, expiring October 19, 2022	$	534,250	$	534,250
$300.0 million Incremental Term Loan (“Incremental Term Loan”) bearing interest at one-month LIBOR (2.09% at June 30, 2018), plus an applicable margin of 3.25% at June 30, 2018, expiring April 3, 2021	285,000		291,000
$143.0 million Senior Secured Revolver (“Senior Secured Revolver”) bearing interest at one-month LIBOR (2.09% at June 30, 2018) plus an applicable margin of 3.5% at June 30, 2018, expiring October 19, 2020	67,962		—
$200.0 million Second Lien Facility ("Second Lien") bearing interest at one-month LIBOR (2.09% at June 30, 2018), plus an applicable margin of 8.0% at June 30, 2018, expiring April 19, 2023	200,000		—
International lines of credit and other loans	4,962		3,315
Total	1,092,174		828,565
Less current maturities of long-term debt	29,809		17,283
Principal, net of current portion	1,062,365		811,282
Less unamortized debt issuance costs	21,931		20,477
Long-term debt, net of current portion	$	1,040,434	$	790,805

We capitalized interest costs amounting to $0.3 million and $0.3 million in the three months ended June 30, 2018 and 2017, and $0.5 million and $0.6 million in the six months ended June 30, 2018 and 2017, related to construction in progress.

Collectively, our Senior Secured Term Loan, Incremental Term Loan, and Senior Secured Revolver comprise our credit facility. Our credit facility is subject to certain financial covenants based on a consolidated net leverage ratio, as defined in the credit facility agreement. The financial covenants are effective when we have outstanding amounts drawn on our Senior Secured Revolver on the last day of any fiscal quarter and become more restrictive over time. We had $68.0 million outstanding balance on the Senior Secured Revolver as of June 30, 2018, and were in compliance with all covenants under our credit facility and expect to be in compliance with all covenants through June 30, 2019.

Second Lien Credit Agreement

In connection with the Paragon Medical acquisition, we, certain of our subsidiaries named therein, SunTrust Bank, as Administrative Agent, SunTrust Robinson Humphrey, Inc. as Lead Arranger and Bookrunner, and the lenders named therein entered into a Second Lien Credit Agreement (the “Second Lien Credit Agreement”) pursuant to which SunTrust and the other lenders extended to us a $200.0 million secured second lien term loan facility (the “Second Lien Facility”). We utilized the net proceeds from the Second Lien Facility, together with cash on hand, to pay the Paragon Medical purchase price and fees and expenses related to the acquisition. The Second Lien Facility is collateralized by all of our assets. The Second Lien Facility matures on April 19, 2023, and bears interest at either (i) a base rate, plus an applicable margin, or (ii) the greater of the London Interbank Offered Rate (“LIBOR”) or 1.00%, plus an applicable margin. The initial applicable margin for all borrowings under the Second Lien Facility is 7.00% per annum with respect to base rate borrowings and 8.00% per annum with respect to LIBOR borrowings. We may voluntarily prepay outstanding loans under the Second Lien Facility, in whole or in part without premium or penalty at any time on or after May 7, 2020. We are subject to a prepayment penalty of 2% of the amount of such loans that we prepay before May 7, 2019. If we prepay any outstanding loans after May 7, 2019, but prior to May 7, 2020, we are subject to a prepayment penalty of 1% of the amount prepaid. The Second Lien Credit Agreement requires us to prepay outstanding loans, subject to certain exceptions, with: (i) a variable percentage of excess cash flow; (ii) 100% of the net cash proceeds of non-ordinary course asset sales or other dispositions of property, and 100% of the net cash proceeds from certain insurance and condemnation events with respect to our assets, subject to customary thresholds and reinvestment rights; and (iii) 100% of the net cash proceeds from the issuance or incurrence of debt obligations for borrowed money not permitted by the Second Lien Credit Agreement.

Amendment to Credit Facility

On May 7, 2018, we entered into an amendment to our existing credit facility to permit the Paragon Medical acquisition, to permit the Second Lien Credit Agreement, and to amend certain covenants. We paid $16.7 million of debt issuance costs related to the amendment. A total of $12.9 million is included in the "Loss on extinguishment of debt and write-off of debt issuance costs" line on the Condensed Consolidated Statements of Operations and Comprehensive Income (Loss). The remaining $3.8 million is capitalized as a reduction of long-term debt.