Consolidated Balance Sheets (Parenthetical) (USD $) In Millions, except Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Other, accumulated amortization of debt issuance costs	$ 24	$ 17
Intangible assets, accumulated amortization	107	77
Series A preferred units, redemption amount	$ 38	$ 85
Common units, authorized	214,287,955	174,574,175
Common units, issued	210,850,232	170,951,457
Common units, outstanding	210,850,232	170,951,457
Class F Units [Member]
Partners' Capital Account, Units	6,274,483	0