Long-Term Debt (Tables)

3 Months Ended

Mar. 31, 2015

Debt Disclosure [Abstract]

Long-Term Debt

`	March 31,			December 31,			March 31,
	2015			2014			2014
	(Dollars in Thousands)
6.6% Senior Notes, due 2018	$	299,182		$	299,123		$	298,949
7% Debentures, due 2025		124,508			124,500			124,478
6.25% Senior Notes, due 2037		228,194			228,184			228,157
4.25% Senior Notes, due 2024		395,410			395,309			—
Floating Rate Notes, due 2017, interest rate of 1.36% and      1.33% at March 31, 2015 and December 31, 2014, respectively		298,980			298,869			—
Term Loan Facility, due 2018, interest rate of 1.67% at March 31,      2015 and December 31, 2014; and 1.65% at March 31, 2014		233,213			236,258			245,395
Revolving Facility, interest rate of 1.89% at March 31, 2014		—			—			20,000
Trade Receivable Facility, interest rate of 0.75% at March 31, 2014		—			—			150,000
Other notes		1,536			3,152			965
Total debt		1,581,023			1,585,395			1,067,944
Less: Current maturities		(14,406	)		(14,336	)		(12,403	)
Long-term debt	$	1,566,617		$	1,571,059		$	1,055,541