Debt and Other Financing Arrangements (Tables)

12 Months Ended

Dec. 31, 2014

Debt Disclosure [Abstract]

Schedule of Debt and Other Financing Arrangements

	(in thousands)
	December 31,
	2014			2013
Industrial revenue bonds:
0.17% to 0.24%, variable, due from 2015 to 2040	$	1,026,935		$	1,030,200
Notes, 5.75%, due 2017		600,000			600,000
Notes, 5.85%, due 2018		500,000			500,000
Notes, 4.125%, due 2022		600,000			600,000
Notes, 4.0%, due 2023		500,000			500,000
Notes, 6.40%, due 2037		650,000			650,000
Notes, 5.20%, due 2043		500,000			500,000
		4,376,935			4,380,200
Less current maturities		(16,335	)		(3,300	)
	$	4,360,600		$	4,376,900