

	December 31,
	2018			2017			Interest rate	Maturity date
Senior Secured Credit Facilities:
Term Loan A	$	675,000		$	775,000		2.00% + LIBOR	6/24/2019
Term Loan A-2	995,000			—			1.00% + LIBOR	6/24/2019
Term Loan B	3,342,500			3,377,500			2.75% + LIBOR⁽²⁾	6/24/2021
Revolver	175,000			300,000			2.00% + LIBOR	6/24/2019
Senior Notes:
5 3/4% Senior Notes	1,250,000			1,250,000			5.75%	8/15/2022
5 1/8% Senior Notes	1,750,000			1,750,000			5.125%	7/15/2024
5% Senior Notes	1,500,000			1,500,000			5%	5/1/2025
Acquisition obligations and other notes payable⁽¹⁾	183,979			150,512			6.24%	2019-2025
Capital lease obligations⁽¹⁾	282,737			297,170			5.49%	2019-2036
Total debt principal outstanding	10,154,216			9,400,182
Discount and deferred financing costs	(52,000		)	(63,951		)
	10,102,216			9,336,231
Less current portion	(1,929,369		)	(178,213		)
	$	8,172,847		$	9,158,018

During the year ended December 31, 2018, the Company made mandatory principal payments under its senior secured credit facilities totaling $100,000 on Term Loan A and $35,000 on Term Loan B.

On March 29, 2018, the Company entered into an Increase Joinder No. 1 (Increase Joinder Agreement) under its existing senior secured credit facilities. Pursuant to this Increase Joinder Agreement, the Company entered into an additional $995,000 Term Loan A-2.

Total outstanding borrowings under Term Loan A, Term Loan A-2 and Term Loan B consist of various individual tranches that can range in maturity from one month to twelve months (currently all tranches are one month in duration). For Term Loan A, Term Loan A-2 and Term Loan B, each tranche bears interest at a London Interbank Offered Rate (LIBOR) that is determined by the duration of such tranche plus an interest rate margin. The LIBOR variable component of the interest rate for each tranche is reset as such tranche matures and a new tranche is established. At December 31, 2018, the overall weighted average interest rate for Term Loan A, Term Loan A-2 and Term Loan B was determined based upon the LIBOR interest rates in effect for all of the individual tranches plus their respective interest rate margins noted in the table above.

The Company maintains several interest rate cap agreements that have the economic effect of capping the LIBOR variable component of the Company’s interest rate at a maximum of 3.50% on $3,500,000 of outstanding principal debt, including all of Term Loan B and part of Term Loan A. However, the remaining $517,500 outstanding principal balance of Term Loan A and the entire outstanding balance on Term Loan A-2 would still be subject to LIBOR-based interest rate volatility. See below for further details. The Company is restricted from paying dividends under the terms of its senior secured credit facilities.

As of December 31, 2018, the Company has $175,000 drawn on its $1,000,000 revolving line of credit under its senior secured credit facilities, in addition to approximately $14,155 committed for outstanding letters of credit. The Company also has approximately $22,621 of additional outstanding letters of credit under a separate bilateral secured letter of credit facility, and $211 of committed outstanding letters of credit which are backed by a certificate of deposit.

The Senior Notes are unsecured obligations, rank equally in right of payment with the Company’s existing and future unsecured senior indebtedness, are guaranteed by substantially all of the Company’s direct and indirect wholly-owned domestic subsidiaries, and require semi-annual interest payments. The Company may redeem some or all of the Senior Notes at any time on or after certain specific dates and at certain specific redemption prices as outlined in each senior note agreement. Interest rates on the Senior Notes are fixed by their terms, and the Company is restricted from paying dividends under the indentures governing its Senior Notes.

As of December 31, 2018, the Company maintains several interest rate cap agreements as a means of hedging its exposure to and volatility from variable-based interest rate changes as part of its overall interest rate risk management strategy. These agreements are not held for trading or speculative purposes and had the economic effect of capping the Company’s maximum exposure to LIBOR variable interest rate changes on specific portions of the Company’s floating rate debt, as described below. These cap agreements are also designated as cash flow hedges and, as a result, changes in the fair values of these cap agreements are reported in other comprehensive income. The amortization of the original cap premium is recognized as a component of debt expense on a straight-line basis over the term of the cap agreements. These cap agreements do not contain credit-risk contingent features.

The Company's current interest rate cap agreements were entered into in October 2015 with notional amounts totaling $3,500,000. These cap agreements became effective June 29, 2018, have the economic effect of capping the LIBOR variable component of the Company’s interest rate at a maximum of 3.50% on an equivalent amount of the Company’s debt, and will expire on June 30, 2020. As of December 31, 2018, the total fair value of these cap agreements was an asset of approximately $851. During the year ended December 31, 2018, the Company recognized debt expense of $4,327 from these cap agreements and recorded a loss of $181 in other comprehensive income due to a decrease in the unrealized fair value of these cap agreements.

Previously, the Company maintained other interest rate cap agreements that were entered into in November 2014 with notional amounts also totaling $3,500,000. These cap agreements had the economic effect of capping the LIBOR variable component of the Company’s interest rate at a maximum of 3.50% on an equivalent amount of the Company’s debt and expired on June 30, 2018. During the year ended 2018, the Company recognized debt expense of $4,140 from these cap agreements and recorded an immaterial loss in other comprehensive income due to a decrease in the unrealized fair value of these cap agreements through expiration.



		Fair value
Derivatives designated as hedging instruments	Balance sheet location	December 31, 2018		December 31, 2017
Interest rate cap agreements	Other long-term assets	$	851	$	1,032



	Amount of unrealized losses in OCI on interest rate cap and swap agreements									Location of losses	Amount of losses reclassified from accumulated OCI into income
	Year ended December 31,										Year ended December 31,
Derivatives designated as cash flow hedges	2018			2017			2016				2018			2017			2016
Interest rate cap agreements	$	(181	)	$	(8,897	)	$	(5,198	)	Debt expense	$	8,466		$	8,278		$	3,899
Interest rate swap agreements	—			—			(815		)	Debt expense	—			—			299
Tax benefit	48			3,460			2,343			Tax expense	(2,180		)	(3,220		)	(1,632		)
Total	$	(133	)	$	(5,437	)	$	(3,670	)		$	6,286		$	5,058		$	2,566

The Company’s overall weighted average effective interest rate on the senior secured credit facilities at the end of 2018 was 5.11%, based upon the current margins in effect as of December 31, 2018.

Debt expense consisted of interest expense of $461,897, $406,341 and $394,013 and the amortization and accretion of debt discounts and premiums, amortization of deferred financing costs and the amortization of interest rate cap agreements of