Financing Receivables: (Details 5) (USD $) In Millions, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Financing Receivable, Recorded Investment [Line Items]
Total	$ 21,681	$ 22,510
Major Markets
Financing Receivable, Recorded Investment [Line Items]
Total	15,747	16,701
Growth Markets
Financing Receivable, Recorded Investment [Line Items]
Total	5,934	5,808
Lease receivables
Financing Receivable, Recorded Investment [Line Items]
Total	8,809	9,174
Lease receivables | Major Markets
Financing Receivable, Recorded Investment [Line Items]
Total	6,705	7,036
Lease receivables | Major Markets | AAA - AA-
Financing Receivable, Recorded Investment [Line Items]
Total	606	646
Lease receivables | Major Markets | A+ - A-
Financing Receivable, Recorded Investment [Line Items]
Total	1,520	1,664
Lease receivables | Major Markets | BBB+ - BBB-
Financing Receivable, Recorded Investment [Line Items]
Total	2,154	2,285
Lease receivables | Major Markets | BB+ - BB
Financing Receivable, Recorded Investment [Line Items]
Total	1,421	1,367
Lease receivables | Major Markets | BB- - B+
Financing Receivable, Recorded Investment [Line Items]
Total	533	552
Lease receivables | Major Markets | B - B-
Financing Receivable, Recorded Investment [Line Items]
Total	356	399
Lease receivables | Major Markets | CCC+ - D-
Financing Receivable, Recorded Investment [Line Items]
Total	115	124
Lease receivables | Growth Markets
Financing Receivable, Recorded Investment [Line Items]
Total	2,104	2,138
Lease receivables | Growth Markets | AAA - AA-
Financing Receivable, Recorded Investment [Line Items]
Total	71	86
Lease receivables | Growth Markets | A+ - A-
Financing Receivable, Recorded Investment [Line Items]
Total	178	223
Lease receivables | Growth Markets | BBB+ - BBB-
Financing Receivable, Recorded Investment [Line Items]
Total	875	776
Lease receivables | Growth Markets | BB+ - BB
Financing Receivable, Recorded Investment [Line Items]
Total	306	450
Lease receivables | Growth Markets | BB- - B+
Financing Receivable, Recorded Investment [Line Items]
Total	412	418
Lease receivables | Growth Markets | B - B-
Financing Receivable, Recorded Investment [Line Items]
Total	198	127
Lease receivables | Growth Markets | CCC+ - D-
Financing Receivable, Recorded Investment [Line Items]
Total	64	58
Loan receivables
Financing Receivable, Recorded Investment [Line Items]
Total	12,871	13,336
Loan receivables | Major Markets
Financing Receivable, Recorded Investment [Line Items]
Total	9,042	9,666
Loan receivables | Major Markets | AAA - AA-
Financing Receivable, Recorded Investment [Line Items]
Total	817	887
Loan receivables | Major Markets | A+ - A-
Financing Receivable, Recorded Investment [Line Items]
Total	2,049	2,286
Loan receivables | Major Markets | BBB+ - BBB-
Financing Receivable, Recorded Investment [Line Items]
Total	2,904	3,139
Loan receivables | Major Markets | BB+ - BB
Financing Receivable, Recorded Investment [Line Items]
Total	1,916	1,878
Loan receivables | Major Markets | BB- - B+
Financing Receivable, Recorded Investment [Line Items]
Total	719	758
Loan receivables | Major Markets | B - B-
Financing Receivable, Recorded Investment [Line Items]
Total	480	548
Loan receivables | Major Markets | CCC+ - D-
Financing Receivable, Recorded Investment [Line Items]
Total	155	170
Loan receivables | Growth Markets
Financing Receivable, Recorded Investment [Line Items]
Total	3,830	3,670
Loan receivables | Growth Markets | AAA - AA-
Financing Receivable, Recorded Investment [Line Items]
Total	129	148
Loan receivables | Growth Markets | A+ - A-
Financing Receivable, Recorded Investment [Line Items]
Total	324	382
Loan receivables | Growth Markets | BBB+ - BBB-
Financing Receivable, Recorded Investment [Line Items]
Total	1,593	1,333
Loan receivables | Growth Markets | BB+ - BB
Financing Receivable, Recorded Investment [Line Items]
Total	557	773
Loan receivables | Growth Markets | BB- - B+
Financing Receivable, Recorded Investment [Line Items]
Total	750	718
Loan receivables | Growth Markets | B - B-
Financing Receivable, Recorded Investment [Line Items]
Total	361	218
Loan receivables | Growth Markets | CCC+ - D-
Financing Receivable, Recorded Investment [Line Items]
Total	$ 116	$ 99