Long term debt and finance lease obligations gross before debt issuance costs.

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Amount of long-term debt and finance lease obligations including current maturities.

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Face (par) amount of debt instrument at time of issuance.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount, after accumulated amortization, of debt discount (premium).

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Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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Present value of lessee's discounted obligation for lease payments from finance lease.

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Present value of lessee's discounted obligation for lease payments from finance lease, classified as current.

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Amount of long-term debt and lease obligation, classified as noncurrent.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt, classified as current. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Debt and Other Financing Arrangements - Schedule of Debt and Other Financing Arrangements (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	May 31, 2020	Dec. 31, 2019	Apr. 30, 2018
Debt Instrument [Line Items]
Finance lease obligations	$ 90,338		$ 85,224
Total long-term debt and finance lease obligations	5,493,578		4,345,824
Less premium on debt exchange	180,045
Less debt issuance costs	30,859	$ 8,400	25,259	$ 11,900
Total amounts outstanding	5,282,674		4,320,565
Less current maturities of long-term debt			20,000
Less current portion of finance lease obligations	10,885		9,264
Total long-term debt and finance lease obligations due after one year	5,271,789		4,291,301
Notes, 4.125%, due 2022 [Member]
Debt Instrument [Line Items]
Debt instrument face amount	600,000		600,000
Notes, 4.000%, due 2023 [Member]
Debt Instrument [Line Items]
Debt instrument face amount	500,000		500,000
Notes, 2.000%, due 2025 [Member]
Debt Instrument [Line Items]
Debt instrument face amount	500,000
Notes, 3.950%, due 2028 [Member]
Debt Instrument [Line Items]
Debt instrument face amount	500,000		500,000	500,000
Notes, 2.700%, due 2030 [Member]
Debt Instrument [Line Items]
Debt instrument face amount	500,000
Notes, 6.400%, due 2037 [Member]
Debt Instrument [Line Items]
Debt instrument face amount	543,331		650,000
Notes, 5.200%, due 2043 [Member]
Debt Instrument [Line Items]
Debt instrument face amount	338,133		500,000
Notes, 4.400%, due 2048 [Member]
Debt Instrument [Line Items]
Debt instrument face amount	329,219		500,000	$ 500,000
Notes, 2.979%, due 2055 [Member]
Debt Instrument [Line Items]
Debt instrument face amount	439,317
Industrial Revenue Bonds [Member] \| Due from 2022 to 2040 [Member]
Debt Instrument [Line Items]
Debt instrument face amount	$ 1,153,240		$ 1,010,600