Financing Receivables: (Details 7) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Past Due Financing Receivable
Total Past Due (> 90 days)	$ 88	$ 82
Current	21,406	22,428
Total Financing Receivables	21,494	22,510
Recorded Investment > 90 Days and Accruing	55	52
Troubled debt restructurings of financing receivables	0	0
Major Markets
Past Due Financing Receivable
Total Financing Receivables	15,670	16,701
Growth Markets
Past Due Financing Receivable
Total Financing Receivables	5,824	5,808
Lease receivables
Past Due Financing Receivable
Total Past Due (> 90 days)	27	20
Current	8,799	9,154
Total Financing Receivables	8,826	9,174
Recorded Investment > 90 Days and Accruing	17	13
Lease receivables | Major Markets
Past Due Financing Receivable
Total Past Due (> 90 days)	11	8
Current	6,766	7,028
Total Financing Receivables	6,776	7,036
Recorded Investment > 90 Days and Accruing	7	5
Lease receivables | Growth Markets
Past Due Financing Receivable
Total Past Due (> 90 days)	16	11
Current	2,033	2,127
Total Financing Receivables	2,049	2,138
Recorded Investment > 90 Days and Accruing	11	8
Loan receivables
Past Due Financing Receivable
Total Past Due (> 90 days)	61	63
Current	12,607	13,273
Total Financing Receivables	12,668	13,336
Recorded Investment > 90 Days and Accruing	38	39
Loan receivables | Major Markets
Past Due Financing Receivable
Total Past Due (> 90 days)	18	27
Current	8,875	9,639
Total Financing Receivables	8,894	9,666
Recorded Investment > 90 Days and Accruing	10	8
Loan receivables | Growth Markets
Past Due Financing Receivable
Total Past Due (> 90 days)	43	36
Current	3,731	3,634
Total Financing Receivables	3,774	3,670
Recorded Investment > 90 Days and Accruing	$ 28	$ 31