Ventures and Variable Interest Entities (Narrative) (Details) (Variable Interest Entity, Primary Beneficiary [Member], USD $) In Millions, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2014 T	Dec. 31, 2013	Dec. 31, 2013 Cash [Member]	Dec. 31, 2013 Property, Plant and Equipment [Member]
Variable Interest Entity [Line Items]
Ownership percentage	50.00%
Contribution from noncontrolling interests			$ 6	$ 103
Expected production capacity per year	1,300,000
Pre-formation costs		$ 70