LONG-TERM DEBT

Long-term debt obligations on the consolidated balance sheet (in millions):



	March 31, 2018			December 31, 2017
Fixed-rate notes payable due through 2028	$	877		$	959
Variable-rate notes payable due through 2028	1,587			1,625
Less debt issuance costs	(15		)	(15		)
Total debt	2,449			2,569
Less current portion	387			307
Long-term debt, less current portion	$	2,062		$	2,262

Weighted-average fixed-interest rate	4.2		%	4.2		%
Weighted-average variable-interest rate	3.3		%	2.8		%

During the three months ended March 31, 2018 the Company made debt payments of $120 million, including the prepayment of $23 million of debt.

At March 31, 2018 long-term debt principal payments for the next five years and thereafter are as follows (in millions):



	Total
Remainder of 2018	$	266
2019	321
2020	439
2021	421
2022	246
Thereafter	768
Total	$	2,461

Bank Lines of Credit

The Company has three credit facilities totaling $475 million. All three facilities have variable interest rates based on LIBOR plus a specified margin. One credit facility for $250 million expires in June 2021 and is secured by aircraft. A second credit facility for $75 million expires in September 2018, with a mechanism for annual renewal, and is secured by aircraft. A third credit facility for $150 million expires in March 2022 and is secured by certain accounts receivable, spare engines, spare parts and ground service equipment. The Company has secured letters of credit against the $75 million facility, but has no plans to borrow using either of the two other facilities. All three credit facilities have a requirement to maintain a minimum unrestricted cash and marketable securities balance of $500 million. The Company was in compliance with this covenant at March 31, 2018.