Operating Segments (Details) $ in Millions | 3 Months Ended | 6 Months Ended | |
Jun. 30, 2020USD ($) | Jun. 30, 2019USD ($) | Jun. 30, 2020USD ($)Businesssegment | Jun. 30, 2019USD ($) | Dec. 31, 2019USD ($) |
Segment Reporting [Abstract] | | | | | |
Number of reportable segments | segment | | | 3 | | |
Segment Reporting Information [Abstract] | | | | | |
Sales | $ 256.1 | $ 245.2 | $ 670 | $ 648.9 | |
Operating earnings (loss) | 24.5 | 4.1 | 68.7 | 37.3 | |
Depreciation, depletion and amortization | 34.9 | 33.9 | 68 | 68.9 | |
Total assets (as of end of period) | 2,085.8 | 2,320.9 | 2,085.8 | 2,320.9 | $ 2,443.2 |
United States | | | | | |
Segment Reporting Information [Abstract] | | | | | |
Sales | 147.7 | 128.3 | 405.6 | 366.6 | |
Canada | | | | | |
Segment Reporting Information [Abstract] | | | | | |
Sales | 24.2 | 27.9 | 101.6 | 115.3 | |
Brazil | | | | | |
Segment Reporting Information [Abstract] | | | | | |
Sales | 74.6 | 79 | 136.8 | 134.7 | |
United Kingdom | | | | | |
Segment Reporting Information [Abstract] | | | | | |
Sales | 5.3 | 5.7 | 17 | 23 | |
Other | | | | | |
Segment Reporting Information [Abstract] | | | | | |
Sales | 4.3 | 4.3 | 9 | 9.3 | |
Shipping and handling cost | | | | | |
Segment Reporting Information [Abstract] | | | | | |
Shipping and handling cost | 40.5 | 48 | 142.3 | 160.9 | |
Highway Deicing Salt | | | | | |
Segment Reporting Information [Abstract] | | | | | |
Sales | 61.6 | 46.9 | 276.7 | 265.6 | |
Consumer & Industrial Salt | | | | | |
Segment Reporting Information [Abstract] | | | | | |
Sales | 60.2 | 65.7 | 132.9 | 153.4 | |
SOP and Specialty Plant Nutrients | | | | | |
Segment Reporting Information [Abstract] | | | | | |
Sales | 119 | 112.6 | 221 | 186.9 | |
Industrial Chemicals | | | | | |
Segment Reporting Information [Abstract] | | | | | |
Sales | 15.6 | 21.3 | 37.4 | 43.9 | |
Operating Segments | Salt | | | | | |
Segment Reporting Information [Abstract] | | | | | |
Sales | 121.8 | 112.6 | 409.6 | 419 | |
Operating earnings (loss) | 29.7 | 14.6 | 86.6 | 66.9 | |
Depreciation, depletion and amortization | 17.2 | 14.8 | 31.8 | 30.1 | |
Total assets (as of end of period) | 943.2 | 905.2 | 943.2 | 905.2 | |
Operating Segments | Salt | Shipping and handling cost | | | | | |
Segment Reporting Information [Abstract] | | | | | |
Shipping and handling cost | 29.7 | 37.6 | 119.5 | 141.3 | |
Operating Segments | Salt | Highway Deicing Salt | | | | | |
Segment Reporting Information [Abstract] | | | | | |
Sales | 61.6 | 46.9 | 276.7 | 265.6 | |
Operating Segments | Salt | Consumer & Industrial Salt | | | | | |
Segment Reporting Information [Abstract] | | | | | |
Sales | 60.2 | 65.7 | 132.9 | 153.4 | |
Operating Segments | Salt | SOP and Specialty Plant Nutrients | | | | | |
Segment Reporting Information [Abstract] | | | | | |
Sales | 0 | 0 | 0 | 0 | |
Operating Segments | Salt | Industrial Chemicals | | | | | |
Segment Reporting Information [Abstract] | | | | | |
Sales | 0 | 0 | 0 | 0 | |
Operating Segments | Salt | Eliminations & Other | | | | | |
Segment Reporting Information [Abstract] | | | | | |
Sales | 0 | 0 | 0 | 0 | |
Operating Segments | Plant Nutrition North America | | | | | |
Segment Reporting Information [Abstract] | | | | | |
Sales | 55.1 | 48.1 | 115.7 | 85.3 | |
Operating earnings (loss) | 5.1 | 4.6 | 10.3 | 3 | |
Depreciation, depletion and amortization | 10.2 | 10.9 | 20.7 | 22.5 | |
Total assets (as of end of period) | 545 | 565.3 | 545 | 565.3 | |
Operating Segments | Plant Nutrition North America | Shipping and handling cost | | | | | |
Segment Reporting Information [Abstract] | | | | | |
Shipping and handling cost | 7.6 | 6.5 | 16.6 | 12.5 | |
Operating Segments | Plant Nutrition North America | Highway Deicing Salt | | | | | |
Segment Reporting Information [Abstract] | | | | | |
Sales | 0 | 0 | 0 | 0 | |
Operating Segments | Plant Nutrition North America | Consumer & Industrial Salt | | | | | |
Segment Reporting Information [Abstract] | | | | | |
Sales | 0 | 0 | 0 | 0 | |
Operating Segments | Plant Nutrition North America | SOP and Specialty Plant Nutrients | | | | | |
Segment Reporting Information [Abstract] | | | | | |
Sales | 57.5 | 50.7 | 118.4 | 88.4 | |
Operating Segments | Plant Nutrition North America | Industrial Chemicals | | | | | |
Segment Reporting Information [Abstract] | | | | | |
Sales | 0 | 0 | 0 | 0 | |
Operating Segments | Plant Nutrition North America | Eliminations & Other | | | | | |
Segment Reporting Information [Abstract] | | | | | |
Sales | (2.4) | (2.6) | $ (2.7) | (3.1) | |
Operating Segments | Plant Nutrition South America | | | | | |
Segment Reporting Information [Line Items] | | | | | |
Number of primary businesses | Business | | | 2 | | |
Segment Reporting Information [Abstract] | | | | | |
Sales | 76.9 | 82.1 | $ 139.7 | 139.8 | |
Operating earnings (loss) | 8.9 | 1.7 | 9.2 | (0.9) | |
Depreciation, depletion and amortization | 4.4 | 5.4 | 9.4 | 11 | |
Total assets (as of end of period) | 553.8 | 731.5 | 553.8 | 731.5 | |
Operating Segments | Plant Nutrition South America | Shipping and handling cost | | | | | |
Segment Reporting Information [Abstract] | | | | | |
Shipping and handling cost | 3.2 | 3.9 | 6.2 | 7.1 | |
Operating Segments | Plant Nutrition South America | Highway Deicing Salt | | | | | |
Segment Reporting Information [Abstract] | | | | | |
Sales | 0 | 0 | 0 | 0 | |
Operating Segments | Plant Nutrition South America | Consumer & Industrial Salt | | | | | |
Segment Reporting Information [Abstract] | | | | | |
Sales | 0 | 0 | 0 | 0 | |
Operating Segments | Plant Nutrition South America | SOP and Specialty Plant Nutrients | | | | | |
Segment Reporting Information [Abstract] | | | | | |
Sales | 61.5 | 61.9 | 102.6 | 98.5 | |
Operating Segments | Plant Nutrition South America | Industrial Chemicals | | | | | |
Segment Reporting Information [Abstract] | | | | | |
Sales | 15.6 | 21.3 | 37.4 | 43.9 | |
Operating Segments | Plant Nutrition South America | Eliminations & Other | | | | | |
Segment Reporting Information [Abstract] | | | | | |
Sales | (0.2) | (1.1) | (0.3) | (2.6) | |
Corporate & Other | | | | | |
Segment Reporting Information [Abstract] | | | | | |
Sales | 2.3 | 2.4 | 5 | 4.8 | |
Operating earnings (loss) | (19.2) | (16.8) | (37.4) | (31.7) | |
Depreciation, depletion and amortization | 3.1 | 2.8 | 6.1 | 5.3 | |
Total assets (as of end of period) | 43.8 | 118.9 | 43.8 | 118.9 | |
Corporate & Other | Shipping and handling cost | | | | | |
Segment Reporting Information [Abstract] | | | | | |
Shipping and handling cost | 0 | 0 | 0 | 0 | |
Corporate & Other | Highway Deicing Salt | | | | | |
Segment Reporting Information [Abstract] | | | | | |
Sales | 0 | 0 | 0 | 0 | |
Corporate & Other | Consumer & Industrial Salt | | | | | |
Segment Reporting Information [Abstract] | | | | | |
Sales | 0 | 0 | 0 | 0 | |
Corporate & Other | SOP and Specialty Plant Nutrients | | | | | |
Segment Reporting Information [Abstract] | | | | | |
Sales | 0 | 0 | 0 | 0 | |
Corporate & Other | Industrial Chemicals | | | | | |
Segment Reporting Information [Abstract] | | | | | |
Sales | 0 | 0 | 0 | 0 | |
Corporate & Other | Eliminations & Other | | | | | |
Segment Reporting Information [Abstract] | | | | | |
Sales | 2.3 | 2.4 | 5 | 4.8 | |
Intersegment Eliminations | | | | | |
Segment Reporting Information [Abstract] | | | | | |
Sales | (2.6) | (3.7) | (3) | (5.7) | |
Intersegment Eliminations | Eliminations & Other | | | | | |
Segment Reporting Information [Abstract] | | | | | |
Sales | (0.3) | (1.3) | 2 | (0.9) | |
Intersegment Eliminations | Salt | | | | | |
Segment Reporting Information [Abstract] | | | | | |
Sales | 0 | 0 | 0 | 0 | |
Intersegment Eliminations | Plant Nutrition North America | | | | | |
Segment Reporting Information [Abstract] | | | | | |
Sales | 2.4 | 2.6 | 2.7 | 3.1 | |
Intersegment Eliminations | Plant Nutrition South America | | | | | |
Segment Reporting Information [Abstract] | | | | | |
Sales | $ 0.2 | $ 1.1 | $ 0.3 | $ 2.6 | |