Income Taxes (Details 3) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Deferred tax liabilities:
Property, plant and equipment and Rail Group assets leased to others	$ (170,588)	$ (133,869)
Prepaid employee benefits	0	(18,453)
Equity method investments	(45,673)	(36,045)
Other	(22,261)	(5,388)
Deferred tax liabilities	(238,522)	(193,755)
Deferred tax assets:
Employee benefits	27,160	52,107
Accounts and notes receivable	2,611	1,784
Inventory	11,918	9,964
Net operating loss carryforwards	4,542	1,155
Other	13,583	148
Total deferred tax assets	59,814	65,158
Valuation allowance	(593)	(232)
Net deferred tax assets	59,221	64,926
Net deferred tax liabilities	$ (179,301)	$ (128,829)