Long-Term Debt (Tables)

3 Months Ended

Mar. 31, 2016

Debt Disclosure [Abstract]

Long-Term Debt

	March 31,			December 31,			March 31,
	2016			2015			2015
	(Dollars in Thousands)
6.6% Senior Notes, due 2018	$	299,201		$	299,113		$	298,842
7% Debentures, due 2025		124,024			124,002			123,938
6.25% Senior Notes, due 2037		227,933			227,917			227,880
4.25 % Senior Notes, due 2024		394,843			394,690			394,304
Floating Rate Notes, due 2017, interest rate of 2.13%,      1.71% and 1.36% at March 31, 2016, December 31, 2015      and March 31, 2015, respectively		298,837			298,868			298,304
Term Loan Facility, due 2018, interest rate of 1.94%, 1.86% and 1.67%      at March 31, 2016, December 31, 2015 and March 31, 2015,      respectively		217,109			222,521			231,259
Revolving Facility, interest rate of 3.75%		30,000			—			—
Trade Receivable Facility, interest rate of 1.13% at March 31, 2016		159,925			—			—
Other notes		885			1,663			1,536
Total debt		1,752,757			1,568,774			1,576,063
Less: Current maturities		(177,430	)		(18,713	)		(13,873	)
Long-term debt	$	1,575,327		$	1,550,061		$	1,562,190