Financing Receivables: (Details 4) (USD $) In Millions, unless otherwise specified	3 Months Ended	9 Months Ended
Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Financing Receivable, Impaired [Line Items]
Recorded Investment	$ 183		$ 183		$ 160
Related Allowance	170		170		143
Average Recorded Investment	174	147	166	154
Interest Income Recognized	0	0	0	0
Interest Income Recognized on Cash Basis	0	0	0	0
Major Markets
Financing Receivable, Impaired [Line Items]
Recorded Investment	74		74		88
Related Allowance	68		68		77
Average Recorded Investment	73	84	76	91
Interest Income Recognized	0	0	0	0
Interest Income Recognized on Cash Basis	0	0	0	0
Growth Markets
Financing Receivable, Impaired [Line Items]
Recorded Investment	109		109		72
Related Allowance	102		102		65
Average Recorded Investment	102	63	90	64
Interest Income Recognized	0	0	0	0
Interest Income Recognized on Cash Basis	$ 0	$ 0	$ 0	$ 0

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Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 15

-Subparagraph (c)(1)

-URI http://asc.fasb.org/extlink&oid=28368275&loc=d3e5212-111524

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 17

-URI http://asc.fasb.org/extlink&oid=28368275&loc=d3e5258-111524

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- Definition

Amount of interest income recognized that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired.

+ References

+ Details

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- Definition

Amount of interest income recognized on a cash-basis method of accounting that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired.

+ References

+ Details

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- Definition

Amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 14A

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=28368275&loc=SL6953550-111524

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- Definition

Amount of allowance for credit losses related to recorded investment.

+ References

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