Debt, Financing Arrangements and Leases (Tables)

12 Months Ended

Dec. 31, 2017

At December 31, 2017 and 2016, long-term debt outstanding was as follows (in thousands):



	2017			2016
Debentures:
7.08% due 2026	$	7,500		$	7,500
7.25% due 2026	200,000			200,000
Total debentures	207,500			207,500

Notes:
6.05% due 2018	250,000			250,000
7.85% due 2026	1,000,000			1,000,000
5.4% due 2041	375,000			375,000
4.45% due 2042	400,000			400,000
Total notes	2,025,000			2,025,000

Other financing obligation	230,926			—

Total long-term debt, including current portion	2,463,426			2,232,500
Unamortized debt issuance costs	(15,377		)	(16,408		)
Unamortized debt premium and discount, net	(5,043		)	(5,338		)
Long-term debt due within one year	(251,430		)	—

Total long-term debt	$	2,191,576		$	2,210,754

Maturities of long-term debt

Aggregate minimum maturities (face value) applicable to long-term debt outstanding at December 31, 2017, for the next five years, are as follows (in thousands):



2018: 6.05% Notes and other financing obligation	$	251,566
2019: Other financing obligation	$	1,721
2020: Other financing obligation	$	1,893
2021: Other financing obligation	$	2,081
2022: Other financing obligation	$	2,289

Future minimum lease payments

The future minimum lease payments under our various operating leases are as follows (in thousands):



2018	$	13,558
2019	14,890
2020	14,860
2021	14,710
2022	14,654
Thereafter	122,333
Total net minimum obligations	$	195,005