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Claims, Lawsuits and Other Contingencies - Narrative (Details) $ in Millions |  |  |  | 3 Months Ended | 12 Months Ended |
--- | --- | --- | --- | --- | --- | ---
Mar. 31, 2020 USD ($) | Sep. 06, 2018 USD ($) | Oct. 03, 2017 NZD ($) | Mar. 31, 2020 USD ($) | Mar. 31, 2019 USD ($) | Dec. 31, 2016 USD ($) | Dec. 31, 2019 USD ($)
Legal, Guarantees and Indemnifications |  |  |  |  |  |  |
Revenue |  |  |  | $ 3,219,000,000 | $ 3,143,000,000 |  |
Maximum potential funding under commitments | $ 70,000,000 |  |  | 70,000,000 |  |  | $ 110,000,000
Letters of credit outstanding | 71,000,000 |  |  | 71,000,000 |  |  | $ 73,000,000
Pending Litigation | Christchurch City Council |  |  |  |  |  |  |
Legal, Guarantees and Indemnifications |  |  |  |  |  |  |
Damages sought | 315,000,000 |  | $ 528 |  |  |  |
Minimum |  |  |  |  |  |  |
Legal, Guarantees and Indemnifications |  |  |  |  |  |  |
Estimate of possible loss | 0 |  |  | 0 |  |  |
Minimum | Pilkington North America, Inc. |  |  |  |  |  |  |
Legal, Guarantees and Indemnifications |  |  |  |  |  |  |
Damages sought |  | $ 45,000,000 |  |  |  |  |
Maximum |  |  |  |  |  |  |
Legal, Guarantees and Indemnifications |  |  |  |  |  |  |
Estimate of possible loss | 100,000,000 |  |  | 100,000,000 |  |  |
Maximum | Pilkington North America, Inc. |  |  |  |  |  |  |
Legal, Guarantees and Indemnifications |  |  |  |  |  |  |
Damages sought |  | 85,000,000 |  |  |  |  |
Damages awarded |  | $ 15,000,000 |  |  |  |  |
Aviation and Aerospace Broking Industry |  |  |  |  |  |  |
Legal, Guarantees and Indemnifications |  |  |  |  |  |  |
Revenue |  |  |  |  |  | $ 100,000,000 |
Discontinued Operations, Disposed of by Sale | Tempo Business | Property Lease Guarantee |  |  |  |  |  |  |
Legal, Guarantees and Indemnifications |  |  |  |  |  |  |
Maximum potential funding under commitments | 66,000,000 |  |  | 66,000,000 |  |  |
Guarantor obligations, current carrying value | 11,000,000 |  |  | 11,000,000 |  |  |
Loss contingency accrual payments |  |  |  | 0 |  |  |
Discontinued Operations, Disposed of by Sale | Tempo Business | Performance Guarantee |  |  |  |  |  |  |
Legal, Guarantees and Indemnifications |  |  |  |  |  |  |
Maximum potential funding under commitments | 139,000,000 |  |  | 139,000,000 |  |  |
Guarantor obligations, current carrying value | $ 1,000,000 |  |  | 1,000,000 |  |  |
Loss contingency accrual payments |  |  |  | $ 0 |  |  |

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