Fair Value Measurements and Derivatives - Additional Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2014	Mar. 31, 2014 Foreign Exchange Forward [Member]	Dec. 31, 2013 Foreign Exchange Forward [Member]	Mar. 31, 2014 Currency Swap [Member]	Dec. 31, 2013 Currency Swap [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Notes receivable sold	$ 75
Notional amounts of derivatives	$ 534	$ 240	$ 252	$ 294	$ 297

The cash inflow associated with the sale of a borrowing supported by a written promise to pay an obligation.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Investing Activities

-URI http://asc.fasb.org/extlink&oid=6516133

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 12

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3179-108585

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration