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, 2012	Dec. 31, 2011	Jun. 30, 2012 Major Markets	Dec. 31, 2011 Major Markets	Jun. 30, 2012 Growth Markets	Dec. 31, 2011 Growth Markets	Jun. 30, 2012 Lease receivables	Dec. 31, 2011 Lease receivables	Dec. 31, 2010 Lease receivables	Jun. 30, 2012 Lease receivables Major Markets	Dec. 31, 2011 Lease receivables Major Markets	Dec. 31, 2010 Lease receivables Major Markets	Jun. 30, 2012 Lease receivables Growth Markets	Dec. 31, 2011 Lease receivables Growth Markets	Dec. 31, 2010 Lease receivables Growth Markets	Jun. 30, 2012 Client loan receivables	Dec. 31, 2011 Client loan receivables	Dec. 31, 2010 Client loan receivables	Jun. 30, 2012 Client loan receivables Major Markets	Dec. 31, 2011 Client loan receivables Major Markets	Dec. 31, 2010 Client loan receivables Major Markets	Jun. 30, 2012 Client loan receivables Growth Markets	Dec. 31, 2011 Client loan receivables Growth Markets	Dec. 31, 2010 Client loan receivables Growth Markets
Financing Receivables:
Ending Balance	$ 19,820	$ 20,060	$ 15,105	$ 15,587	$ 4,715	$ 4,472	$ 8,259	$ 8,430		$ 6,423	$ 6,510		$ 1,836	$ 1,921		$ 11,561	$ 11,629		$ 8,682	$ 9,077		$ 2,879	$ 2,552
Collectively evaluated for impairment	19,581	19,692	14,971	15,321	4,610	4,370
Individually evaluated for impairment	239	368	134	266	105	102
Allowance for Credit Losses
Allowance for credit losses, beginning balance	307	353	203	234	104	119	116	118	126	71	79	84	45	40	42	182	189	226	117	125	150	65	64	76
Write-offs	(5)	(84)	(4)	(68)	(1)	(16)
Provision	(1)	44	(9)	39	8	5
Other	(3)	(5)	(2)	(1)	(1)	(4)
Allowance for credit losses, ending balance	298	307	188	203	110	104	116	118	126	71	79	84	45	40	42	182	189	226	117	125	150	65	64	76
Collectively evaluated for impairment	104	96	85	82	19	15
Individually evaluated for impairment	$ 194	$ 211	$ 103	$ 122	$ 91	$ 89