Financing Arrangements and Long-Term Debt (Schedule of Long Term Debt) (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Notes payable	$ 2,800,000	$ 2,800,000
Unamortized discount on notes payable	(23,627)	(27,433)
Total notes payable, net of unamortized discount	2,776,373	2,772,567
Capitalized lease obligation, due through June 2029	136,344	143,855
Total debt including current maturities	2,912,717	2,916,422
Senior Unsecured Revolving Credit Facility	325,000
Current maturities	(10,583)	(9,902)
Total long-term debt	$ 3,227,134	2,906,520
Capital lease expiration date	Mar. 01, 2029
4.00% notes, due June 2022 [Member]
Debt Instrument [Line Items]
Notes payable	$ 500,000	500,000
Interest rate	4.00%
Debt Instrument, Maturity Month And Year	June 2022
4.45% notes, due December 2022 [Member]
Debt Instrument [Line Items]
Notes payable	$ 600,000	$ 600,000
Interest rate	4.45%	4.70%
Debt Instrument, Maturity Month And Year	December 2022
6.875% notes, due August 15, 2024 [Member]
Debt Instrument [Line Items]
Notes payable	$ 550,000	$ 550,000
Interest rate	6.875%
Debt Instrument, Maturity Month And Year	August 2024
5.75% notes, due August 2025 [Member]
Debt Instrument [Line Items]
Notes payable	$ 550,000	550,000
Interest rate	5.75%
Debt Instrument, Maturity Month And Year	August 2025
7.05% notes, due May 2029 [Member]
Debt Instrument [Line Items]
Notes payable	$ 250,000	250,000
Interest rate	7.05%
Debt Instrument, Maturity Month And Year	May 2029
5.875% notes, due December 2042 [Member]
Debt Instrument [Line Items]
Notes payable	$ 350,000	$ 350,000
Interest rate	5.875%	6.125%
Debt Instrument, Maturity Month And Year	December 2042

Debt Instrument, Maturity Month And Year

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Amount equal to the present value (the principal) at the beginning of the lease term of minimum lease payments during the lease term (excluding that portion of the payments representing executory costs such as insurance, maintenance, and taxes to be paid by the lessor, together with any profit thereon) net of payments or other amounts applied to the principal through the balance sheet date.

+ References

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-Publisher FASB
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Sum of the carrying values as of the balance sheet date of all debt, including all short-term borrowings, long-term debt, and capital lease obligations.

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Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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Contractual interest rate for funds borrowed, under the debt agreement.

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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.

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- Definition

Date which lease or group of leases is set to expire, in CCYY-MM-DD format.

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- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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

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Amount of long-term debt and capital lease obligation due after one year or beyond the normal operating cycle, if longer.

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Amount of long-term debt and capital leases due within one year or the normal operating cycle, if longer.

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