Long-Term Debt (Schedule Of Indebtedness) (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Long-term debt	$ 8,198,419	$ 7,380,443
Long-term debt, fair value	310,057	248,856
5.50% Senior Notes due October 18, 2023 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 741,529	$ 741,264
Interest rate	5.50%	5.50%
Principal	$ 750,000	$ 750,000
6.625% Senior Notes due October 23, 2043 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 246,638	$ 246,627
Interest rate	6.625%	6.625%
Principal	$ 250,000	$ 250,000
5.125% Senior Notes, due April 13, 2018 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 814,623	$ 817,813
Interest rate	5.125%	5.125%
Principal	$ 800,000	$ 800,000
8.5% Senior Notes, due July 15, 2019 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 771,253	$ 778,367
Interest rate	8.50%	8.50%
Principal	$ 700,000	$ 700,000
2.375% Euro Senior Notes, due May 20, 2020 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 528,220	$ 528,250
Interest rate	2.375%	2.375%
Principal	$ 529,825	$ 529,975
6.875% Senior Notes, due April 15, 2021 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 819,951	$ 823,797
Interest rate	6.875%	6.875%
Principal	$ 750,000	$ 750,000
2.25% Euro Medium Term Notes, due July 13, 2022 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 3,863	$ 3,848
Interest rate	2.25%	2.25%
Principal	$ 4,239	$ 4,240
5.125% Senior Notes, due January 20, 2023 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 617,704	$ 618,355
Interest rate	5.125%	5.125%
Principal	$ 600,000	$ 600,000
4.85% Senior Notes, due January 15, 2027 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 738,748	$ 0
Interest rate	4.85%	0.00%
Principal	$ 750,000	$ 0
6.45% Senior Debentures, due June 8, 2027 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 377,313	$ 377,806
Interest rate	6.45%	6.45%
Principal	$ 350,000	$ 350,000
3.875% Convertible Senior Debentures, due November 1, 2029 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 345,850	$ 346,163
Interest rate	3.875%	3.875%
Principal	$ 345,000	$ 345,000
6.25% Senior Debentures, due January 15, 2036 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 512,309	$ 512,396
Interest rate	6.25%	6.25%
Principal	$ 500,000	$ 500,000
6.50% Senior Notes, due January 20, 2043 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 421,249	$ 421,333
Interest rate	6.50%	6.50%
Principal	$ 400,000	$ 400,000
Structured Notes [Member]
Debt Instrument [Line Items]
Long-term debt	316,408	255,203
Long-term debt, fair value	310,100	248,900
54 Madison Debt [Member]
Debt Instrument [Line Items]
Long-term debt	387,822	406,028
Foursight Credit Facilities [Member]
Debt Instrument [Line Items]
Long-term debt	154,327	97,138
Other [Member]
Debt Instrument [Line Items]
Long-term debt	127,769	132,244
Parent Company [Member]
Debt Instrument [Line Items]
Long-term debt	988,167	987,891
National Beef [Member] | National Beef Term Loan [Member]
Debt Instrument [Line Items]
Long-term debt	$ 266,250	273,811
Interest rate	2.53%
National Beef [Member] | National Beef Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Long-term debt	$ 6,593	0
Interest rate	4.75%
Subsidiaries [Member]
Debt Instrument [Line Items]
Long-term debt	$ 7,210,252	$ 6,392,552
Interest Rate Swap [Member] | 4.85% Senior Notes, due January 15, 2027 [Member]
Debt Instrument [Line Items]
Decrease of long-term debt	$ 5,400