Financing Receivables: (Details) (USD $) In Millions, unless otherwise specified					3 Months Ended				3 Months Ended				3 Months Ended				3 Months Ended
	Mar. 31, 2012	Dec. 31, 2011	Mar. 31, 2012 Net investment in sales-type and direct financing leases	Dec. 31, 2011 Net investment in sales-type and direct financing leases	Mar. 31, 2012 Net investment in sales-type and direct financing leases Financing receivable, upper range of payment terms Y	Mar. 31, 2012 Net investment in sales-type and direct financing leases Financing receivable, lower range of payment terms Y	Mar. 31, 2012 Commercial financing receivables	Dec. 31, 2011 Commercial financing receivables	Mar. 31, 2012 Commercial financing receivables Financing receivable, upper range of payment terms D	Mar. 31, 2012 Commercial financing receivables Financing receivable, lower range of payment terms D	Mar. 31, 2012 Client loan receivables	Dec. 31, 2011 Client loan receivables	Mar. 31, 2012 Client loan receivables Financing receivable, upper range of payment terms Y	Mar. 31, 2012 Client loan receivables Financing receivable, lower range of payment terms Y	Mar. 31, 2012 Installment payment receivables	Dec. 31, 2011 Installment payment receivables	Mar. 31, 2012 Installment payment receivables Financing receivable, upper range of payment terms Y	Mar. 31, 2012 Installment payment receivables Financing receivable, lower range of payment terms Y
Financing receivables, current
Financing receivables, net, current	$ 15,160	$ 16,901	$ 3,819	$ 3,765			$ 5,476	$ 7,095			$ 4,822	$ 5,195			$ 1,045	$ 846
Financing receivables, noncurrent
Financing receivables, net, noncurrent	10,549	10,776	5,293	5,406			7	34			4,912	4,925			337	410
Financing receivables
Financing receivable, payment terms (in years/days)					6	2			90	30			7	1			3	1
Sales-type and direct financing leases, unguaranteed residual value			730	745
Sales-type and direct financing leases, unearned income			732	733
Allowance for credit losses			117	118			39	53			150	126			33	51
Financing receivables used as collateral for non-recourse borrowings	$ 373	$ 324