Debt

Long-term debt at December 31, 2017 and 2018 was as follows (in thousands):



	December 31,
	2017			2018
6.40% Notes due 2018	$	250,000		$	—
6.55% Notes due 2019⁽¹⁾	550,000			550,000
4.25% Notes due 2021	550,000			550,000
3.20% Notes due 2025	250,000			250,000
5.00% Notes due 2026	650,000			650,000
6.40% Notes due 2037	250,000			250,000
4.20% Notes due 2042	250,000			250,000
5.15% Notes due 2043	550,000			550,000
4.20% Notes due 2045	250,000			250,000
4.25% Notes due 2046	500,000			500,000
4.20% Notes due 2047	500,000			500,000
Face value of long-term debt	4,550,000			4,300,000
Unamortized debt issuance costs⁽²⁾	(29,472		)	(27,070		)
Net unamortized debt premium (discount)⁽²⁾	215			(2,927		)
Net unamortized amount of gains from historical fair value hedges⁽²⁾	3,749			866
Long-term debt, net, including current portion	4,524,492			4,270,869
Less: current portion of long-term debt, net⁽¹⁾	250,974			59,489
Long-term debt, net	$	4,273,518		$	4,211,380

(1)

At December 31, 2018, we had the ability and the intent to refinance approximately $490.0 million of our long-term notes maturing in 2019. As a result, only the portion of our debt that will be repaid with cash available as of December 31, 2018 is classified as current in our consolidated balance sheets. See Note 19 – Subsequent Events for details regarding proceeds received from our debt issuance in January 2019.


(2)	Debt issuance costs, note discounts and premiums and realized gains and losses of historical fair value hedges are being amortized or accreted to the applicable notes over the respective lives of those notes.

All of the instruments detailed in the table above are senior indebtedness.

At December 31, 2018, maturities of our debt were as follows: $550.0 million in July 2019; $0 in 2020; $550 in 2021; $0 in 2022; $0 in 2023; and $3.2 billion thereafter. See Note 19 – Subsequent Events for details regarding early redemption of the notes due in July 2019.

Other Debt

Revolving Credit Facility. At December 31, 2018, the total borrowing capacity under our revolving credit facility maturing October 26, 2022 was $1.0 billion. Any borrowings outstanding under this facility are classified as long-term debt on our consolidated balance sheets. Borrowings under the facility are unsecured and bear interest at LIBOR plus a spread ranging from 1.000% to 1.625% based on our credit ratings. Additionally, an unused commitment fee is assessed at a rate from 0.100% to 0.275% depending on our credit ratings. The unused commitment fee was 0.125% at December 31, 2018. Borrowings under this facility may be used for general purposes, including capital expenditures. As of December 31, 2017 and 2018, respectively, there were obligations for letters of credit of $6.3 million and $6.8 million, respectively. Amounts obligated for letters of credit are not reflected as debt on our consolidated balance sheets, but decrease our borrowing capacity under the facility. There were no borrowings outstanding under this facility at December 31, 2017 and 2018.

Our revolving credit facility requires us to maintain a specified ratio of consolidated debt to EBITDA (as defined in the credit agreement) of no greater than 5.0 to 1.0. In addition, the revolving credit facility and the indentures under which our senior notes were issued contain covenants that limit our ability to, among other things, incur indebtedness secured by certain liens or encumber our assets, engage in certain sale-leaseback transactions and consolidate, merge or dispose of all or substantially all of our assets. We were in compliance with these covenants as of and during the year ended December 31, 2018.

Commercial Paper Program. We have a commercial paper program under which we may issue commercial paper notes in an amount up to the available capacity under our $1.0 billion revolving credit facility. The maturities of the commercial paper notes vary, but may not exceed 397 days from the date of issuance. Because the commercial paper we can issue is limited to amounts available under our revolving credit facility, amounts outstanding under the program are classified as long-term debt. The commercial paper notes are sold under customary terms in the commercial paper market and are issued at a discount from par, or alternatively, are sold at par and bear varying interest rates on a fixed or floating basis. The weighted-average interest rate for commercial paper borrowings based on the number of days outstanding was 1.3% and 2.3%, respectively, for the year ended December 31, 2017 and 2018.

During the years ending December 31, 2016, 2017 and 2018, total cash payments for interest on all indebtedness, excluding the impact of related interest rate swap agreements, were $181.7 million, $206.2 million and $227.8 million, respectively.