Commitments and Contingencies (Schedule Of Activity Related To Asbestos Claim) (Detail)	3 Months Ended					6 Months Ended		12 Months Ended
	Jun. 30, 2019 USD ($) Claim	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Jun. 30, 2019 USD ($) Claim	Jun. 30, 2018 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Oct. 06, 2016 USD ($)	Apr. 22, 2016 USD ($)	Feb. 09, 2016 USD ($)	Jul. 02, 2015 USD ($)	Jun. 16, 2014 USD ($)	Sep. 17, 2013 USD ($)	Mar. 01, 2013 USD ($)	Feb. 25, 2013 USD ($)	Feb. 23, 2011 USD ($)	Mar. 23, 2010 USD ($)
Loss Contingencies [Line Items]
Document Period End Date						Jun. 30, 2019
Current asbestos liability	$ 66,000,000.0					$ 66,000,000.0		$ 66,000,000.0
Payments for asbestos-related fees and costs, net of insurance recoveries						17,900,000	$ 34,900,000
Asbestos Commitments and Contingencies
Loss Contingencies [Line Items]
Asbestos Settlement Cost Per Resolved Claim								$ 11,300	$ 7,800	$ 3,900
Current asbestos liability	$ 66,000,000					$ 66,000,000
Number of buyout agreements with excess insurer groups	10					10
Aggregate Value Of Policy Buy Out Agreements	$ 82,500,000					$ 82,500,000
Beginning claims	28,498	30,990				29,089	32,234	32,234
New claims	769	620				1,444	1,228	2,434
Settlements	(178)	(332)				(586)	(605)	(1,011)
Dismissals	(238)	(1,358)				(1,096)	(2,937)	(4,568)
Ending claims	28,851	29,920				28,851	29,920	29,089	32,234
Gross Settlement And Defense Incurred Costs	$ 13,800,000	$ 41,100,000				$ 40,300,000	$ 55,900,000	$ 88,800,000
Payments for asbestos-related fees and costs, net of insurance recoveries	$ 8,200,000	$ 32,000,000.0				$ 17,900,000	$ 34,900,000	$ 63,900,000
New York | Asbestos Commitments and Contingencies
Loss Contingencies [Line Items]
Ending claims | Claim	18,000					18,000
Texas | Asbestos Commitments and Contingencies
Loss Contingencies [Line Items]
Ending claims | Claim	100					100
Mississippi | Asbestos Commitments and Contingencies
Loss Contingencies [Line Items]
Ending claims | Claim	300					300
OHIO | Asbestos Commitments and Contingencies
Loss Contingencies [Line Items]
Ending claims | Claim	200					200
James Nelson | Asbestos Commitments and Contingencies
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
Share Of Responsibility Of Verdict																				9.09%
Thomas Amato [Member] | Asbestos Commitments and Contingencies
Loss Contingencies [Line Items]
Jury Verdict																		$ 2,500,000
Share Of Responsibility Of Verdict																		10.00%
PaidJuryVerdict			$ 300,000
Frank Vincinguerra [Member] | Asbestos Commitments and Contingencies
Loss Contingencies [Line Items]
Jury Verdict																		$ 2,300,000
Share Of Responsibility Of Verdict																		20.00%
PaidJuryVerdict					$ 600,000
Ivo Peraica | Asbestos Commitments and Contingencies
Loss Contingencies [Line Items]
Court Judgment																	$ 10,600,000
Court_Reduced_Verdict																	18,000,000
Paid Judgment Pursuant to Appeal				$ 2,700,000
Jury Verdict Total																	$ 35,000,000
Reduced Damages											$ 4,250,000
CourtJudgmentIncludingSetoffs											1,940,000
Richard DeLisle [Member] | Asbestos Commitments and Contingencies
Loss Contingencies [Line Items]
Jury Verdict																$ 8,000,000
Court Judgment																$ 1,300,000
Share Of Responsibility Of Verdict																16.00%
Ivan Sweberg [Member] | Asbestos Commitments and Contingencies
Loss Contingencies [Line Items]
Court Judgment															$ 5,300,000
Court_Reduced_Verdict															10,000,000
Paid Judgment Pursuant to Appeal				$ 5,700,000
Jury Verdict Total															15,000,000
Reduced Damages											9,500,000
CourtJudgmentIncludingSetoffs											4,730,000
Selwyn Hackshaw [Member] | Asbestos Commitments and Contingencies
Loss Contingencies [Line Items]
Court Judgment															3,100,000
Court_Reduced_Verdict															6,000,000
Jury Verdict Total															$ 10,000,000
Reduced Damages											3,000,000
CourtJudgmentIncludingSetoffs											$ 0
James Poage [Member] | Asbestos Commitments and Contingencies
Loss Contingencies [Line Items]
Court Judgment														$ 10,800,000
compensatory_damages														1,500,000
Additional Damages														$ 10,000,000
Valent Rabovsky [Member] | Asbestos Commitments and Contingencies
Loss Contingencies [Line Items]
Court Judgment												$ 400,000
Share Of Responsibility Of Verdict													30.00%
Jury Verdict Total													$ 1,085,000.000
George Coulbourn [Member] | Asbestos Commitments and Contingencies
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
Geoffrey_Anisansel [Member] | Asbestos Commitments and Contingencies
Loss Contingencies [Line Items]
Jury Verdict Total			$ 20,000,000