Condensed Consolidating Financial Information of Guarantor Subsidiaries - CONDENSED CONSOLIDATING CASH FLOW INFORMATION (Details) - USD ($) $ in Millions	9 Months Ended
Sep. 30, 2017	Sep. 30, 2016
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	$ 1,766	$ 1,630
Net cash (used in) provided by investing activities	(2,252)	(865)
Net cash provided by (used in) financing activities	477	(656)
Effect of foreign exchange rates	21	9
Net increase in cash and cash equivalents	12	118
Cash and cash equivalents at beginning of period	312	179
Cash and cash equivalents at end of period	324	297
Eliminations
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	0	0
Net cash (used in) provided by investing activities	0	0
Net cash provided by (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
Parent \| Reportable Legal Entities
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	15	4
Net cash (used in) provided by investing activities	(15)	(4)
Net cash provided by (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 \| Reportable Legal Entities
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	1,849	1,513
Net cash (used in) provided by investing activities	(2,145)	(862)
Net cash provided by (used in) financing activities	298	(649)
Effect of foreign exchange rates	0	0
Net increase in cash and cash equivalents	2	2
Cash and cash equivalents at beginning of period	21	18
Cash and cash equivalents at end of period	23	20
Guarantor Subsidiaries \| Reportable Legal Entities
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	(2)	(2)
Net cash (used in) provided by investing activities	0	0
Net cash provided by (used in) financing activities	2	2
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 \| Reportable Legal Entities
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	83	108
Net cash (used in) provided by investing activities	(92)	1
Net cash provided by (used in) financing activities	(2)	(2)
Effect of foreign exchange rates	21	9
Net increase in cash and cash equivalents	10	116
Cash and cash equivalents at beginning of period	291	161
Cash and cash equivalents at end of period	301	277
Non-Guarantor Subsidiaries - SPV \| Reportable Legal Entities
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	(179)	7
Net cash (used in) provided by investing activities	0	0
Net cash provided by (used in) financing activities	179	(7)
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

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.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section 45
-Paragraph 1
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