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CHANGES IN BUSINESS (Details) $ in Millions |  | 1 Months Ended | 3 Months Ended | 12 Months Ended
--- | --- | --- | --- | ---
Nov. 05, 2018 USD ($) fabrication_facility mini_mill | Oct. 31, 2019 USD ($) | May 31, 2018 USD ($) | Aug. 31, 2020 USD ($) location mini_mill | Aug. 31, 2018 USD ($)
Business Combinations [Abstract] |  |  |  |  |
Number of rebar fabrication facilities acquired | fabrication_facility | 33 |  |  |  |
Number of electric arc furnace mini mills | mini_mill | 4 |  |  | 7 |
Cash purchase price | $ 701.2 |  |  |  |
Net sales of acquired business |  |  |  | $ 1,400.0 |
Net earnings of acquired business |  |  |  | 132.7 |
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] |  |  |  |  |
Facility closure costs |  | $ 9.8 |  | $ 6.2 |
Number of facilities idled | location |  |  |  | 6 |
Severance costs |  |  |  |  | $ 6.7
Structural Steel Fabrication Operations |  |  |  |  |
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] |  |  |  |  |
Proceeds from sale of business |  |  | $ 20.3 |  |
Nonrecurring impairment charge |  |  | $ 13.7 |  |
Australian Steel Trading Business |  |  |  |  |
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] |  |  |  |  |
Currency translation gain (loss) |  |  |  |  | 2.1
Pre-tax gain (loss) |  |  |  |  | $ 5.3

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