Mezzanine Equity (Schedule Of Redeemable Noncontrolling Interests) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Redeemable Noncontrolling Interest [Roll Forward]
Beginning balance			$ 426,593
Income allocated to redeemable noncontrolling interests	$ 390	$ 36,216	37,294	$ 64,538
Increase in fair value of redeemable noncontrolling interests			(28,136)	(24,404)
Reversal of cumulative National Beef redeemable noncontrolling interests fair value adjustment prior to deconsolidation			(237,669)
Ending balance	21,385		21,385
National Beef
Redeemable Noncontrolling Interest [Roll Forward]
Beginning balance			412,128	321,962
Income allocated to redeemable noncontrolling interests		36,600	37,141	65,088
Distributions to redeemable noncontrolling interests			(70,681)	(37,029)
Increase in fair value of redeemable noncontrolling interests			21,404	24,404
Reversal of cumulative National Beef redeemable noncontrolling interests fair value adjustment prior to deconsolidation			(237,669)	0
Deconsolidation of National Beef			(162,323)	0
Ending balance	$ 0	$ 374,425	$ 0	$ 374,425