Long-Term Debt (Tables)

3 Months Ended

Mar. 31, 2017

Debt Disclosure [Abstract]

Long-Term Debt

	March 31,			December 31,			March 31,
	2017			2016			2016
	(Dollars in Thousands)
6.6% Senior Notes, due 2018	$	299,579		$	299,483		$	299,201
7% Debentures, due 2025		124,112			124,090			124,024
6.25% Senior Notes, due 2037		227,989			227,975			227,933
4.25 % Senior Notes, due 2024		395,392			395,252			394,843
Floating Rate Notes, due 2017, interest rate of 2.10%      at March 31, 2017 and December 31, 2016 and 1.36%      at March 31, 2016		298,878			299,033			298,837
Term Loan Facility, due 2018, interest rate of 1.94% at March 31, 2016		—			—			217,109
Revolving Facility, due 2021, interest rate of 1.89%, 1.86% and 3.75%     at March 31, 2017, December 31, 2016 and March 31, 2016,      respectively		210,000			160,000			30,000
Trade Receivable Facility, interest rate of 1.51%, 1.34% and 1.13% at      March 31, 2017, December 31, 2016 and March 31, 2016,      respectively		290,000			180,000			159,925
Other notes		344			356			885
Total debt		1,846,294			1,686,189			1,752,757
Less: Current maturities of long-term debt and short-term facilities		(290,048	)		(180,036	)		(177,430	)
Long-term debt	$	1,556,246		$	1,506,153		$	1,575,327