Condensed Consolidating Financial Information of Guarantor Subsidiaries CONDENSED CONSOLIDATING CASH FLOW INFORMATION (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Condensed Financial Statements, Captions
Net cash provided by (used in) operating activities	$ 1,054	$ 878
Net cash used in investing activities	(1,570)	(801)
Net cash provided by (used in) financing activities	512	(43)
Effect of foreign exchange rates	(1)	(7)
Net (decrease) increase in cash and cash equivalents	(5)	27
Cash and cash equivalents at beginning of period	175	106
Cash and cash equivalents at end of period	170	133
Parent
Condensed Financial Statements, Captions
Net cash provided by (used in) operating activities	10	17
Net cash used in investing activities	(10)	(17)
Net cash provided by (used in) financing activities	0	0
Effect of foreign exchange rates	0	0
Net (decrease) 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 Financial Statements, Captions
Net cash provided by (used in) operating activities	928	717
Net cash used in investing activities	(1,402)	(710)
Net cash provided by (used in) financing activities	483	(20)
Effect of foreign exchange rates	0	0
Net (decrease) increase in cash and cash equivalents	9	(13)
Cash and cash equivalents at beginning of period	17	20
Cash and cash equivalents at end of period	26	7
Guarantor Subsidiaries
Condensed Financial Statements, Captions
Net cash provided by (used in) operating activities	2	(2)
Net cash used in investing activities	0	0
Net cash provided by (used in) financing activities	(2)	2
Effect of foreign exchange rates	0	0
Net (decrease) 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 Financial Statements, Captions
Net cash provided by (used in) operating activities	146	122
Net cash used in investing activities	(158)	(74)
Net cash provided by (used in) financing activities	(1)	(1)
Effect of foreign exchange rates	(1)	(7)
Net (decrease) increase in cash and cash equivalents	(14)	40
Cash and cash equivalents at beginning of period	158	86
Cash and cash equivalents at end of period	144	126
Non Guarantor Subsidiaries SPV
Condensed Financial Statements, Captions
Net cash provided by (used in) operating activities	(32)	24
Net cash used in investing activities	0	0
Net cash provided by (used in) financing activities	32	(24)
Effect of foreign exchange rates	0	0
Net (decrease) 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 Financial Statements, Captions
Net cash provided by (used in) operating activities	0	0
Net cash used in investing activities	0	0
Net cash provided by (used in) financing activities	0	0
Effect of foreign exchange rates	0	0
Net (decrease) 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