Financing Receivables - Past Due (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Past Due Financing Receivable
Total Recorded Investment	$ 28,795	$ 30,877
Total Lease Receivable and Loan Receivable Portfolio Segments
Past Due Financing Receivable
Total Recorded Investment	18,711	19,259
Recorded Investment Not Accruing	322	331
Recorded investment, impaired financing receivables with related allowance	265	269
Impaired financing receivables, related allowance	251	250
Total Lease Receivable and Loan Receivable Portfolio Segments | Total Past Due > 90 days
Past Due Financing Receivable
Recorded Investment > 90 Days	780	825
Recorded Investment > 90 Days and Accruing	470	507
Billed Invoices > 90 Days and Accruing	70	77
Total Lease Receivable and Loan Receivable Portfolio Segments | Americas
Past Due Financing Receivable
Total Recorded Investment	10,170	10,626
Total Lease Receivable and Loan Receivable Portfolio Segments | EMEA
Past Due Financing Receivable
Total Recorded Investment	4,829	4,946
Total Lease Receivable and Loan Receivable Portfolio Segments | Asia Pacific
Past Due Financing Receivable
Total Recorded Investment	3,712	3,687
Lease receivables
Past Due Financing Receivable
Total Recorded Investment	6,594	6,593
Recorded Investment Not Accruing	85	107
Lease receivables | Total Past Due > 90 days
Past Due Financing Receivable
Recorded Investment > 90 Days	353	328
Recorded Investment > 90 Days and Accruing	269	225
Billed Invoices > 90 Days and Accruing	32	36
Lease receivables | Americas
Past Due Financing Receivable
Total Recorded Investment	3,898	3,911
Recorded Investment Not Accruing	38	44
Lease receivables | Americas | Total Past Due > 90 days
Past Due Financing Receivable
Recorded Investment > 90 Days	278	239
Recorded Investment > 90 Days and Accruing	242	197
Billed Invoices > 90 Days and Accruing	27	29
Lease receivables | EMEA
Past Due Financing Receivable
Total Recorded Investment	1,337	1,349
Recorded Investment Not Accruing	17	27
Lease receivables | EMEA | Total Past Due > 90 days
Past Due Financing Receivable
Recorded Investment > 90 Days	26	32
Recorded Investment > 90 Days and Accruing	9	5
Billed Invoices > 90 Days and Accruing	1	3
Lease receivables | Asia Pacific
Past Due Financing Receivable
Total Recorded Investment	1,359	1,333
Recorded Investment Not Accruing	29	36
Lease receivables | Asia Pacific | Total Past Due > 90 days
Past Due Financing Receivable
Recorded Investment > 90 Days	48	57
Recorded Investment > 90 Days and Accruing	19	23
Billed Invoices > 90 Days and Accruing	3	3
Loan receivables
Past Due Financing Receivable
Total Recorded Investment	12,118	12,667
Recorded Investment Not Accruing	237	224
Loan receivables | Total Past Due > 90 days
Past Due Financing Receivable
Recorded Investment > 90 Days	427	498
Recorded Investment > 90 Days and Accruing	200	283
Billed Invoices > 90 Days and Accruing	38	41
Loan receivables | Americas
Past Due Financing Receivable
Total Recorded Investment	6,272	6,715
Recorded Investment Not Accruing	103	96
Loan receivables | Americas | Total Past Due > 90 days
Past Due Financing Receivable
Recorded Investment > 90 Days	265	345
Recorded Investment > 90 Days and Accruing	168	254
Billed Invoices > 90 Days and Accruing	31	38
Loan receivables | EMEA
Past Due Financing Receivable
Total Recorded Investment	3,493	3,597
Recorded Investment Not Accruing	80	74
Loan receivables | EMEA | Total Past Due > 90 days
Past Due Financing Receivable
Recorded Investment > 90 Days	103	90
Recorded Investment > 90 Days and Accruing	23	17
Billed Invoices > 90 Days and Accruing	3	0
Loan receivables | Asia Pacific
Past Due Financing Receivable
Total Recorded Investment	2,353	2,354
Recorded Investment Not Accruing	54	54
Loan receivables | Asia Pacific | Total Past Due > 90 days
Past Due Financing Receivable
Recorded Investment > 90 Days	60	63
Recorded Investment > 90 Days and Accruing	9	12
Billed Invoices > 90 Days and Accruing	$ 4	$ 3