Long-Term Debt (Tables)

6 Months Ended

Jun. 30, 2016

Debt Disclosure [Abstract]

Long-Term Debt

	June 30,			December 31,			June 30,
	2016			2015			2015
	(Dollars in Thousands)
6.6% Senior Notes, due 2018	$	299,294		$	299,113		$	298,931
7% Debentures, due 2025		124,046			124,002			123,960
6.25% Senior Notes, due 2037		227,947			227,917			227,898
4.25 % Senior Notes, due 2024		394,977			394,690			394,441
Floating Rate Notes, due 2017, interest rate of 1.73%,      1.71% and 1.38% at June 30, 2016, December 31, 2015      and June 30, 2015, respectively		298,793			298,868			298,514
Term Loan Facility, due 2018, interest rate of 1.96%, 1.86% and 1.69%      at June 30, 2016, December 31, 2015 and June 30, 2015,      respectively		213,571			222,521			228,346
Trade Receivable Facility, interest rate of 1.16% and 0.88% at      June 30, 2016 and June 30, 2015, respectively		220,000			—			80,000
Other notes		589			1,663			1,248
Total debt		1,779,217			1,568,774			1,653,338
Less: Current maturities		(238,155	)		(18,713	)		(15,433	)
Long-term debt	$	1,541,062		$	1,550,061		$	1,637,905