Quarterly Financial Data (Details Textual) (USD $) In Millions, unless otherwise specified	3 Months Ended			12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Dec. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Property, Plant and Equipment [Line Items]
Long-lived asset impairment charges	$ 90	$ 30		$ 90	$ 0	$ 8
Litigation settlement charge		48		48	0	0
Contract termination charge and loss on receivable	15			15	0	0
Pension settlement charges	13		16	13	16	0
Self-unloading ocean vessels
Property, Plant and Equipment [Line Items]
Long-lived asset impairment charges	$ 60			$ 60