Debt, Financing Arrangements and Leases (Tables)

12 Months Ended

Dec. 31, 2016

Debt Disclosure [Abstract]

Long-term debt

At December 31, 2016 and 2015, long-term debt issues were outstanding as follows (in thousands):

	2016			2015
Debentures:
7.08% due 2026	$	7,500		$	7,500
7.25% due 2026	200,000			200,000
Total debentures	207,500			207,500
Notes:
6.4% due 2016	—			200,000
6.05% due 2018	250,000			250,000
7.85% due 2026	1,000,000			—
5.4% due 2041	375,000			375,000
4.45% due 2042	400,000			400,000
Total notes	2,025,000			1,225,000
Total long-term debt issues	2,232,500			1,432,500
Unamortized debt issuance costs	(16,408		)	(9,069		)
Unamortized debt premium and discount, net	(5,338		)	(3,857		)
Total long-term debt	$	2,210,754		$	1,419,574

Maturities of long-term debt

Aggregate minimum maturities (face value) applicable to long-term debt outstanding at December 31, 2016, for the next five years, are as follows (in thousands):

2018:     6.05% Notes $250,000

Future minimum lease payments

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

2017	$	13,535
2018	13,539
2019	11,114
2020	11,085
2021	3,268
Thereafter	1,763
Total net minimum obligations	$	54,304