Income Taxes (Details 3) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Deferred tax liabilities:
Property, plant and equipment and railcar assets leased to others	$ (110,472)	$ (85,556)
Prepaid employee benefits	(17,725)	(16,490)
Investments	(29,749)	(23,180)
Other	(5,426)	(6,402)
Total deferred tax liabilities	(163,372)	(131,628)
Deferred tax assets:
Employee benefits	36,593	45,400
Accounts and notes receivable	1,890	1,920
Inventory	6,605	4,800
Deferred expenses	689	11,540
Net operating loss carryforwards	631	654
Other	1,905	5,038
Total deferred tax assets	48,313	69,352
Valuation allowance	(92)
Net deferred tax assets	48,221	69,352
Net deferred tax liabilities	$ (115,151)	$ (62,276)