BORROWINGS - Long-Term Debt, Components (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Borrowings
Long-term debt, gross	$ 41,145	$ 38,820
Less: net unamortized discount	839	838
Less: unamortized debt issuance costs	82	74
Add: fair value adjustment	669	790
Long-term debt (including current maturities)	40,893	38,699
Less: current maturities	6,239	5,271
Total long-term debt (excluding current portion)	34,655	33,428
IBM International Group Capital, LLC
Borrowings
Long-term debt, gross	$ 0
Ownership interest in subsidiary (as a percent)	100.00%
U.S. dollars
Borrowings
Long-term debt, gross	$ 30,563	30,319
Euros
Borrowings
Long-term debt, gross	$ 7,122	4,892
Debt instrument, average interest rate percentage (as a percent)	1.60%
Pound sterling
Borrowings
Long-term debt, gross	$ 1,296	1,555
Debt instrument, average interest rate percentage (as a percent)	2.70%
Japanese yen
Borrowings
Long-term debt, gross	$ 1,576	1,180
Debt instrument, average interest rate percentage (as a percent)	0.90%
Swiss francs
Borrowings
Long-term debt, gross	$ 7	9
Debt instrument, average interest rate percentage (as a percent)	6.30%
Canadian
Borrowings
Long-term debt, gross	$ 373	360
Debt instrument, average interest rate percentage (as a percent)	2.20%
Other
Borrowings
Long-term debt, gross	$ 208	506
Debt instrument, average interest rate percentage (as a percent)	11.00%
Maturing 2017 \| U.S. dollars
Borrowings
Long-term debt, gross	$ 5,104	9,351
Debt instrument, average interest rate percentage (as a percent)	3.98%
Maturing 2018 Through 2019 \| U.S. dollars
Borrowings
Long-term debt, gross	$ 8,856	7,591
Debt instrument, average interest rate percentage (as a percent)	3.21%
Maturing 2020 Through 2021 \| U.S. dollars
Borrowings
Long-term debt, gross	$ 4,941	3,717
Debt instrument, average interest rate percentage (as a percent)	1.84%
Maturing 2022 \| U.S. dollars
Borrowings
Long-term debt, gross	$ 1,901	1,900
Debt instrument, average interest rate percentage (as a percent)	2.35%
Maturing 2023 \| U.S. dollars
Borrowings
Long-term debt, gross	$ 1,500	1,500
Debt instrument, average interest rate percentage (as a percent)	3.38%
Maturing 2024 \| U.S. dollars
Borrowings
Long-term debt, gross	$ 2,000	2,000
Debt instrument, average interest rate percentage (as a percent)	3.63%
Maturing 2025 \| U.S. dollars
Borrowings
Long-term debt, gross	$ 600	600
Debt instrument, average interest rate percentage (as a percent)	7.00%
Maturing 2026 \| U.S. dollars
Borrowings
Long-term debt, gross	$ 1,350
Debt instrument, average interest rate percentage (as a percent)	3.45%
Maturing 2027 \| U.S. dollars
Borrowings
Long-term debt, gross	$ 469	469
Debt instrument, average interest rate percentage (as a percent)	6.22%
Maturing 2028 \| U.S. dollars
Borrowings
Long-term debt, gross	$ 313	313
Debt instrument, average interest rate percentage (as a percent)	6.50%
Maturing 2032 \| U.S. dollars
Borrowings
Long-term debt, gross	$ 600	600
Debt instrument, average interest rate percentage (as a percent)	5.88%
Maturing 2038 \| U.S. dollars
Borrowings
Long-term debt, gross	$ 83	83
Debt instrument, average interest rate percentage (as a percent)	8.00%
Maturing 2039 \| U.S. dollars
Borrowings
Long-term debt, gross	$ 745	745
Debt instrument, average interest rate percentage (as a percent)	5.60%
Maturing 2042 \| U.S. dollars
Borrowings
Long-term debt, gross	$ 1,107	1,107
Debt instrument, average interest rate percentage (as a percent)	4.00%
Maturing 2045 \| U.S. dollars
Borrowings
Long-term debt, gross	$ 27	27
Debt instrument, average interest rate percentage (as a percent)	7.00%
Maturing 2046 \| U.S. dollars
Borrowings
Long-term debt, gross	$ 650
Debt instrument, average interest rate percentage (as a percent)	4.70%
Maturing 2096 \| U.S. dollars
Borrowings
Long-term debt, gross	$ 316	$ 316
Debt instrument, average interest rate percentage (as a percent)	7.13%

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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