Income Taxes (Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Employee benefit accruals	$ 11,709	$ 12,801
Impairment of investments	9,772	4,131
Impact of timing of settlement payments	19,313	20,551
Disallowed interest expense carryforward	0	1,619
Various U.S. state tax loss carryforwards	4,296	5,137
Operating lease liabilities	3,679
Other	2,274	1,966
Deferred tax assets	51,043	46,205
Less: Valuation allowance	(1,292)	(3,817)
Net deferred tax assets	49,751	42,388
Deferred tax liabilities:
Basis differences on non-consolidated entities	(7,990)	(7,752)
Basis differences on fixed and intangible assets	(35,082)	(35,854)
Capitalized interest expense	0	(6,532)
Basis differences on inventory	(10,645)	(11,497)
Basis differences on long-term investments	(22,424)	(16,496)
Impact of accounting for convertible debt	(813)	(385)
Basis differences on available for sale securities	(3,219)	(1,283)
Operating lease right of use assets	(3,273)
Deferred tax liabilities	(83,446)	(79,799)
Net deferred tax liabilities	$ (33,695)	$ (37,411)