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v3.19.3.a.u2

Summary of Significant Accounting Policies, Narrative, Property, Plant and Equipment (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Property, Plant and Equipment |  |  |
Interest expense capitalized as construction in progress | $ 1.6 | $ 1.7 | $ 2.2
Depreciation expense | 46.3 | 42.1 | 38.3
Non-cash asset impairment charges | 26.1 | 1.4 | 19.2
Fabricated Products | Idled equipment |  |  |
Property, Plant and Equipment |  |  |
Non-cash asset impairment charges | $ 0.9 | $ 1.4 | $ 0.8
Minimum | Land improvements |  |  |
Property, Plant and Equipment |  |  |
Property, plant and equipment useful lives (in years) | 3 years |  |
Minimum | Buildings and leasehold improvements |  |  |
Property, Plant and Equipment |  |  |
Property, plant and equipment useful lives (in years) | 5 years |  |
Minimum | Machinery and equipment |  |  |
Property, Plant and Equipment |  |  |
Property, plant and equipment useful lives (in years) | 1 year |  |
Minimum | Finance lease assets |  |  |
Property, Plant and Equipment |  |  |
Property, plant and equipment useful lives (in years) | 2 years |  |
Maximum | Land improvements |  |  |
Property, Plant and Equipment |  |  |
Property, plant and equipment useful lives (in years) | 25 years |  |
Maximum | Buildings and leasehold improvements |  |  |
Property, Plant and Equipment |  |  |
Property, plant and equipment useful lives (in years) | 45 years |  |
Maximum | Machinery and equipment |  |  |
Property, Plant and Equipment |  |  |
Property, plant and equipment useful lives (in years) | 22 years |  |
Maximum | Finance lease assets |  |  |
Property, Plant and Equipment |  |  |
Property, plant and equipment useful lives (in years) | 15 years |  |

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