Financing Receivables: (Details 7) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Past Due Financing Receivable
Total Past Due (> 90 days)	$ 75	$ 82
Current	21,449	22,428
Total Financing Receivables	21,524	22,510
Recorded Investment > 90 Days and Accruing	43	52
Troubled debt restructurings of financing receivables	0	0
Major Markets
Past Due Financing Receivable
Total Financing Receivables	15,511	16,701
Growth Markets
Past Due Financing Receivable
Total Financing Receivables	6,013	5,808
Lease receivables
Past Due Financing Receivable
Total Past Due (> 90 days)	21	20
Current	8,937	9,154
Total Financing Receivables	8,958	9,174
Recorded Investment > 90 Days and Accruing	13	13
Lease receivables | Major Markets
Past Due Financing Receivable
Total Past Due (> 90 days)	9	8
Current	6,814	7,028
Total Financing Receivables	6,823	7,036
Recorded Investment > 90 Days and Accruing	4	5
Lease receivables | Growth Markets
Past Due Financing Receivable
Total Past Due (> 90 days)	12	11
Current	2,123	2,127
Total Financing Receivables	2,135	2,138
Recorded Investment > 90 Days and Accruing	9	8
Client loan receivables
Past Due Financing Receivable
Total Past Due (> 90 days)	54	63
Current	12,512	13,273
Total Financing Receivables	12,566	13,336
Recorded Investment > 90 Days and Accruing	30	39
Client loan receivables | Major Markets
Past Due Financing Receivable
Total Past Due (> 90 days)	14	27
Current	8,673	9,639
Total Financing Receivables	8,688	9,666
Recorded Investment > 90 Days and Accruing	6	8
Client loan receivables | Growth Markets
Past Due Financing Receivable
Total Past Due (> 90 days)	40	36
Current	3,839	3,634
Total Financing Receivables	3,878	3,670
Recorded Investment > 90 Days and Accruing	$ 24	$ 31