Commitments And Contingencies (Asbestos Liability Narrative) (Details)	12 Months Ended
	Dec. 31, 2020 USD ($) claim	Dec. 31, 2019 USD ($) claim	Dec. 31, 2018 USD ($) claim	Dec. 31, 2017 claim	Apr. 22, 2016 USD ($)	Jul. 02, 2015 USD ($)	Sep. 17, 2013 USD ($)	Feb. 23, 2011 USD ($)	Mar. 23, 2010 USD ($)
Loss Contingencies [Line Items]
Payments Or Receipts For Asbestos Related Fees And Costs Net Of Insurance Recoveries	$ 31,100,000	$ 41,500,000	$ 63,900,000
Current asbestos liability	$ 66,500,000	$ 65,000,000.0
Asbestos Commitments And Contingencies [Member]
Loss Contingencies [Line Items]
Pending claims | claim	29,138	29,056	29,089	32,234
Gross Settlement And Defense Incurred Costs	$ 50,900,000	$ 66,200,000	$ 88,800,000
Payments Or Receipts For Asbestos Related Fees And Costs Net Of Insurance Recoveries	$ 31,100,000	41,500,000	63,900,000
Asbestos Cumulative Claims Resolved | claim	141,000
Cumulative Related Settlement Cost Incurred Before Insurance Recoveries	$ 680,000,000
Cumulative Asbestos Settlement Cost Per Resolved Claim	4,800
Asbestos Settlement Cost Per Resolved Claim	13,900	15,800	$ 11,300
Estimated Funds Available From Post Bankruptcy Trusts To Pay Current And Future Claimants	36,000,000,000
Asbestos Liability	670,000,000	$ 712,000,000
Percentage Of Asbestos Liability Attributable To Settlement And Denfese Costs For Future Claims		85.00%
Current asbestos liability	66,500,000	$ 65,000,000.0
Aggregate Value Of Policy Buy Out Agreements	82,500,000
Estimated Percentage Of Insurance Which Covers Asbestos Costs		14.00%
Insurance Receivable Asbestos	$ 87,000,000	$ 98,000,000
Asbestos Commitments And Contingencies [Member] | James Nelson [Member]
Loss Contingencies [Line Items]
Jury Verdict									$ 14,500,000
Court Judgment Against All Parties Held Responsible								$ 4,000,000.0
Additional Judgment Interest								$ 10,000.00
Asbestos Commitments And Contingencies [Member] | Richard DeLisle [Member]
Loss Contingencies [Line Items]
Jury Verdict							$ 8,000,000
Court Judgment							$ 1,300,000
Share Of Responsibility Of Verdict							16.00%
Asbestos Commitments And Contingencies [Member] | James Poage [Member]
Loss Contingencies [Line Items]
Court Judgment						$ 10,800,000
compensatory_damages						1,500,000
Additional Damages						$ 10,000,000
Asbestos Commitments And Contingencies [Member] | George Coulbourn [Member]
Loss Contingencies [Line Items]
Court Judgment					$ 6,800,000
Share Of Responsibility Of Verdict					20.00%
Jury Verdict Total					$ 9,000,000
Additional Damages					$ 5,000,000
NEW YORK | Asbestos Commitments And Contingencies [Member]
Loss Contingencies [Line Items]
Pending claims | claim	18,000