Condensed Consolidating Financial Information of Guarantor Subsidiaries - CONDENSED CONSOLIDATING CASH FLOW INFORMATION (Details) - USD ($) $ in Millions	6 Months Ended
Jun. 30, 2015	Jun. 30, 2014
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by operating activities	$ 1,250	$ 1,054
Net cash used in investing activities	(876)	(1,570)
Net cash used in financing activities	(318)	512
Effect of foreign exchange rates	(14)	(1)
Net increase (decrease) in cash and cash equivalents	42	(5)
Cash and cash equivalents at beginning of period	158	175
Cash and cash equivalents at end of period	200	170
Parent
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by operating activities	6	10
Net cash used in investing activities	(6)	(10)
Net cash used in financing activities	0	0
Effect of foreign exchange rates	0	0
Net increase (decrease) in cash and cash equivalents	0	0
Cash and cash equivalents at beginning of period	0	0
Cash and cash equivalents at end of period	0	0
URNA
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by operating activities	1,069	928
Net cash used in investing activities	(793)	(1,402)
Net cash used in financing activities	(280)	483
Effect of foreign exchange rates	0	0
Net increase (decrease) in cash and cash equivalents	(4)	9
Cash and cash equivalents at beginning of period	8	17
Cash and cash equivalents at end of period	4	26
Guarantor Subsidiaries
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by operating activities	1	2
Net cash used in investing activities	0	0
Net cash used in financing activities	(1)	(2)
Effect of foreign exchange rates	0	0
Net increase (decrease) in cash and cash equivalents	0	0
Cash and cash equivalents at beginning of period	0	0
Cash and cash equivalents at end of period	0	0
Non Guarantor Subsidiaries - Foreign
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by operating activities	144	146
Net cash used in investing activities	(77)	(158)
Net cash used in financing activities	(7)	(1)
Effect of foreign exchange rates	(14)	(1)
Net increase (decrease) in cash and cash equivalents	46	(14)
Cash and cash equivalents at beginning of period	150	158
Cash and cash equivalents at end of period	196	144
Non Guarantor Subsidiaries - SPV
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by operating activities	30	(32)
Net cash used in investing activities	0	0
Net cash used in financing activities	(30)	32
Effect of foreign exchange rates	0	0
Net increase (decrease) in cash and cash equivalents	0	0
Cash and cash equivalents at beginning of period	0	0
Cash and cash equivalents at end of period	0	0
Eliminations
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by operating activities	0	0
Net cash used in investing activities	0	0
Net cash used in financing activities	0	0
Effect of foreign exchange rates	0	0
Net increase (decrease) in cash and cash equivalents	0	0
Cash and cash equivalents at beginning of period	0	0
Cash and cash equivalents at end of period	$ 0	$ 0

Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

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Amount of increase (decrease) in cash and cash equivalents. Cash and cash equivalents are the amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Includes effect from exchange rate changes.

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Amount of cash inflow (outflow) from financing activities, including discontinued operations. Financing activity cash flows include obtaining resources from owners and providing them with a return on, and a return of, their investment; borrowing money and repaying amounts borrowed, or settling the obligation; and obtaining and paying for other resources obtained from creditors on long-term credit.

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Amount of cash inflow (outflow) from investing activities, including discontinued operations. Investing activity cash flows include making and collecting loans and acquiring and disposing of debt or equity instruments and property, plant, and equipment and other productive assets.

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