Financing Receivables: (Details 2) (USD $) In Millions, unless otherwise specified	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended
	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2013 Major Markets	Dec. 31, 2012 Major Markets	Jun. 30, 2013 Growth Markets	Dec. 31, 2012 Growth Markets	Jun. 30, 2013 Lease receivables	Dec. 31, 2012 Lease receivables	Dec. 31, 2011 Lease receivables	Jun. 30, 2013 Lease receivables Major Markets	Dec. 31, 2012 Lease receivables Major Markets	Dec. 31, 2011 Lease receivables Major Markets	Jun. 30, 2013 Lease receivables Growth Markets	Dec. 31, 2012 Lease receivables Growth Markets	Dec. 31, 2011 Lease receivables Growth Markets	Jun. 30, 2013 Loan receivables	Dec. 31, 2012 Loan receivables	Dec. 31, 2011 Loan receivables	Jun. 30, 2013 Loan receivables Major Markets	Dec. 31, 2012 Loan receivables Major Markets	Dec. 31, 2011 Loan receivables Major Markets	Jun. 30, 2013 Loan receivables Growth Markets	Dec. 31, 2012 Loan receivables Growth Markets	Dec. 31, 2011 Loan receivables Growth Markets
Financing Receivables
Ending Balance	$ 21,494	$ 22,510	$ 15,670	$ 16,701	$ 5,824	$ 5,808	$ 8,826	$ 9,174		$ 6,776	$ 7,036		$ 2,049	$ 2,138		$ 12,668	$ 13,336		$ 8,894	$ 9,666		$ 3,774	$ 3,670
Collectively evaluated for impairment	21,232	22,254	15,561	16,570	5,671	5,684
Individually evaluated for impairment	262	256	109	131	153	125
Allowance for Credit Losses
Allowance for credit losses, beginning balance	318	307	180	203	138	104	111	114	118	48	59	79	63	55	40	200	204	189	96	121	125	104	84	64
Write-offs	(23)	(15)	(20)	(14)	(4)	(1)
Provision	23	28	(14)	(9)	37	38
Other	(7)	(2)	(3)	0	(4)	(2)
Allowance for credit losses, ending balance	311	318	144	180	168	138	111	114	118	48	59	79	63	55	40	200	204	189	96	121	125	104	84	64
Collectively evaluated for impairment	81	98	50	69	31	29
Individually evaluated for impairment	$ 230	$ 220	$ 94	$ 111	$ 136	$ 109