Environmental	12 Months Ended
Dec. 31, 2020
Environmental Expense and Liabilities [Abstract]
Environmental	EnvironmentalWe expensed $7.1 million, $11.2 million and $14.8 million for the years ended December 31, 2020, 2019 and 2018, respectively, for environmental remediation obligations. The accrued environmental liability reflected in our consolidated balance sheets was $115.0 million and $117.7 million at December 31, 2020 and 2019, respectively, of which $94.0 million and $95.6 million, respectively, were classified as other long-term liabilities. These accruals include remediation and monitoring costs expected to be incurred over an extended period of time (up to 30 years for certain projects). Estimated liabilities could increase in the future when the results of ongoing investigations become known, are considered probable and can be reasonably estimated.

The entire disclosure for environmental loss contingencies, such as presence of hazardous waste, relevant information from reports issued by regulators, and estimated costs to achieve compliance with regulatory requirements. This element may be used for all of an entity's disclosures about environmental loss contingencies.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 30
-URI http://asc.fasb.org/subtopic&trid=2175709

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