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Fair Value Measurements - Narrative (Details) - USD ($) $ in Millions | 3 Months Ended | 12 Months Ended |
--- | --- | --- | ---
Mar. 31, 2015 | Dec. 31, 2013 | Mar. 31, 2014 | Mar. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |
Carrying amount of liabilities | $ 9,700 |  |  | $ 8,100
Brazil Distribution Business |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |
Pre tax impairment charges | 241 |  |  |
Impairment charges, after tax | 235 |  |  |
International Technology |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |
Pre tax impairment charges |  | $ 80 |  |
Impairment charges, after tax |  | $ 80 |  |
Level 2 | Fair Value, Measurements, Recurring |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |
Estimated fair value of liabilities | 10,400 |  |  | $ 8,600
Level 3 | Fair Value, Measurements, Nonrecurring | Brazil Distribution Business |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |
Pre tax impairment charges | 241 |  |  |
Impairment charges, after tax | $ 235 |  |  |
Level 3 | Fair Value, Measurements, Nonrecurring | International Technology |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |
Pre tax impairment charges |  |  | $ 80 |

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