Senior Long-Term Debt And Other Debt (Summary Of Senior Long-Term Debt And Other Debt) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Jun. 30, 2016
Debt Instrument [Line Items]
Senior long-term debt and other debt	$ 3,009,577	$ 3,099,230
Unsecured Senior Notes [Member] \| 7.125% Unsecured Senior Notes Due September 30, 2019 [Member]
Debt Instrument [Line Items]
Unsecured senior notes	$ 234,640	$ 234,411
Debt instrument, interest rate	7.125%	7.125%	7.125%
Debt instrument, unamortized discount	$ 142	$ 332
Unsecured Senior Notes [Member] \| 6.25% Unsecured Senior Notes Due September 30, 2020 [Member]
Debt Instrument [Line Items]
Unsecured senior notes	$ 367,213	$ 376,616
Debt instrument, interest rate	6.25%	6.25%
Debt Instrument, unamortized premium	$ 17,213	$ 26,618
Unsecured Senior Notes [Member] \| 5.35% Unsecured Senior Notes Due June 1, 2021 [Member]
Debt Instrument [Line Items]
Unsecured senior notes	$ 249,417	$ 249,176
Debt instrument, interest rate	5.35%	5.35%
Debt instrument, unamortized discount	$ 499	$ 706
Unsecured Senior Notes [Member] \| 4.90% Unsecured Senior Notes Due July 1, 2022 [Member]
Debt Instrument [Line Items]
Unsecured senior notes	$ 348,864	$ 348,540
Debt instrument, interest rate	4.90%	4.90%
Debt instrument, unamortized discount	$ 978	$ 1,257
Unsecured Senior Notes [Member] \| 3.625% Unsecured Senior Notes Due March 30, 2023 [Member]
Debt Instrument [Line Items]
Unsecured senior notes	$ 248,988	$ 248,749
Debt instrument, interest rate	3.625%	3.625%
Debt instrument, unamortized discount	$ 855	$ 1,056
Unsecured Senior Notes [Member] \| 3.50% Unsecured Senior Notes Due November 1, 2027 [Member]
Debt Instrument [Line Items]
Unsecured senior notes	$ 297,035	$ 296,728
Debt instrument, interest rate	3.50%	3.50%
Debt instrument, unamortized discount	$ 2,298	$ 2,558
Unsecured Senior Notes [Member] \| 7.35% Unsecured Senior Notes Due August 15, 2034 [Member]
Debt Instrument [Line Items]
Unsecured senior notes	$ 128,715	$ 128,642
Debt instrument, interest rate	7.35%	7.35%	7.35%
Debt instrument, unamortized discount	$ 1,074	$ 1,143
Unsecured Senior Notes [Member] \| 5.0% Unsecured Senior Notes Due March 30, 2043 [Member]
Debt Instrument [Line Items]
Unsecured senior notes	$ 244,269	$ 244,033
Debt instrument, interest rate	5.00%	5.00%
Debt instrument, unamortized discount	$ 5,431	$ 5,655
Unsecured Senior Notes [Member] \| 5.0% Unsecured Senior Notes Due April 5, 2046 [Member]
Debt Instrument [Line Items]
Unsecured senior notes	$ 492,486	$ 492,219
Debt instrument, interest rate	5.00%	5.00%	5.00%
Debt instrument, unamortized discount	$ 6,664	$ 6,909
Unsecured Senior Notes [Member] \| 4.30% Unsecured Senior Notes Due November 1, 2047 [Member]
Debt Instrument [Line Items]
Unsecured senior notes	$ 294,975	$ 294,834
Debt instrument, interest rate	4.30%	4.30%
Debt instrument, unamortized discount	$ 4,278	$ 4,451
Other Debt [Member]
Debt Instrument [Line Items]
Senior long-term debt and other debt	$ 102,975	$ 185,282
Other Debt [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate	1.70%
Other Debt [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate	6.30%

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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-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
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Contractual interest rate for funds borrowed, under the debt agreement.

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Amount, after accumulated amortization, of debt discount.

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