Condensed Consolidating Financial Information of Guarantor Subsidiaries - CONDENSED CONSOLIDATING CASH FLOW INFORMATION (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by operating activities	$ 675	$ 508
Net cash used in investing activities	(225)	(231)
Net cash used in financing activities	(335)	(218)
Effect of foreign exchange rates	(16)	(7)
Net increase in cash and cash equivalents	99	52
Cash and cash equivalents at beginning of period	158	175
Cash and cash equivalents at end of period	257	227
Parent
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by operating activities	3	3
Net cash used in investing activities	(3)	(3)
Net cash used in financing activities	0	0
Effect of foreign exchange rates	0	0
Net increase 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	507	390
Net cash used in investing activities	(193)	(219)
Net cash used in financing activities	(264)	(165)
Effect of foreign exchange rates	0	0
Net increase in cash and cash equivalents	50	6
Cash and cash equivalents at beginning of period	8	17
Cash and cash equivalents at end of period	58	23
Guarantor Subsidiaries
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by operating activities	1	1
Net cash used in investing activities	0	0
Net cash used in financing activities	(1)	(1)
Effect of foreign exchange rates	0	0
Net increase 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	95	62
Net cash used in investing activities	(29)	(9)
Net cash used in financing activities	(1)	0
Effect of foreign exchange rates	(16)	(7)
Net increase in cash and cash equivalents	49	46
Cash and cash equivalents at beginning of period	150	158
Cash and cash equivalents at end of period	199	204
Non Guarantor Subsidiaries - SPV
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by operating activities	69	52
Net cash used in investing activities	0	0
Net cash used in financing activities	(69)	(52)
Effect of foreign exchange rates	0	0
Net increase 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 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