Property Plant and Equipment - Schedule of Property Plant and Equipment (Detail) - USD ($) $ in Millions |
Mar. 31, 2016 |
Dec. 31, 2015 |
|---|---|---|
| Property, plant and equipment | ||
| Property, plant and equipment, at cost | $ 2,773.4 | $ 2,793.0 |
| Less: accumulated depreciation | 1,233.6 | 1,236.5 |
| Property, plant and equipment, net | 1,539.8 | 1,556.5 |
| Chemical Manufacturing Plants [Member] | ||
| Property, plant and equipment | ||
| Property, plant and equipment, at cost | 1,299.1 | 1,308.8 |
| Machinery and Equipment [Member] | ||
| Property, plant and equipment | ||
| Property, plant and equipment, at cost | 1,057.6 | 1,080.4 |
| Buildings [Member] | ||
| Property, plant and equipment | ||
| Property, plant and equipment, at cost | 134.9 | 134.7 |
| Land and Land Improvements [Member] | ||
| Property, plant and equipment | ||
| Property, plant and equipment, at cost | 154.2 | 156.6 |
| Construction-in-Progress [Member] | ||
| Property, plant and equipment | ||
| Property, plant and equipment, at cost | $ 127.6 | $ 112.5 |