Debt and Other Financing Arrangements (Tables)

12 Months Ended

Dec. 31, 2019

Debt Disclosure [Abstract]

Schedule of Debt and Other Financing Arrangements

	(in thousands)
December 31,	2019		2018
Industrial revenue bonds due from 2020 to 2040*	$	1,010,600	$	1,010,600
Notes, 4.125%, due 2022		600,000		600,000
Notes, 4.0%, due 2023		500,000		500,000
Notes, 3.95%, due 2028		500,000		500,000
Notes, 6.40%, due 2037		650,000		650,000
Notes, 5.20%, due 2043		500,000		500,000
Notes, 4.40%, due 2048		500,000		500,000
Finance lease obligations		85,224		—
Total long-term debt and finance lease obligations		4,345,824		4,260,600
Less debt issuance costs		25,259		27,324
Total amounts outstanding		4,320,565		4,233,276
Less current maturities of long-term debt		20,000		—
Less current portion of finance lease obligations		9,264		—
Total long-term debt and finance lease obligations due after one year	$	4,291,301	$	4,233,276

* The industrial revenue bonds had variable rates ranging from 1.61% to 1.82% at December 31, 2019 and 1.88% to 2.03% at December 31, 2018.