Debt

3 Months Ended

Mar. 31, 2020

Long-term debt at December 31, 2019 and March 31, 2020 was as follows (in thousands):



	December 31, 2019			March 31, 2020
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
4.85% Notes due 2049	500,000			500,000
3.95% Notes due 2050	500,000			500,000
Face value of long-term debt	4,750,000			4,750,000
Unamortized debt issuance costs⁽¹⁾	(35,263		)	(34,743		)
Net unamortized debt discount⁽¹⁾	(8,662		)	(8,871		)
Long-term debt, net, including current portion	4,706,075			4,706,386
Less: Current portion of long-term debt, net	—			550,949
Long-term debt, net	$	4,706,075		$	4,155,437


(1)	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.

Other Debt

Revolving Credit Facilities. At March 31, 2020, the total borrowing capacity under our revolving credit facility maturing in May 2024 was $1.0 billion. Any borrowings outstanding under this facility are classified as

long-term debt on our consolidated balance sheets. Borrowings under this facility are unsecured and bear interest at LIBOR plus a spread ranging from 0.875% to 1.500% based on our credit ratings. Additionally, an unused commitment fee is assessed at a rate between 0.075% and 0.200% depending on our credit ratings. The unused commitment fee was 0.125% at March 31, 2020. Borrowings under this facility may be used for general partnership purposes, including capital expenditures. As of December 31, 2019 and March 31, 2020, there were no borrowings outstanding under this facility and $3.5 million obligated for letters of credit. Amounts obligated for letters of credit are not reflected as debt on our consolidated balance sheets, but decrease our borrowing capacity under this facility.

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.