Commitments and Contingencies (Asbestos Liability) (Detail)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2020 USD ($) claim	Jun. 30, 2019 USD ($) claim	Jun. 30, 2020 USD ($) claim	Jun. 30, 2019 USD ($) claim	Dec. 31, 2019 USD ($) claim	Dec. 31, 2018 USD ($) claim	Dec. 31, 2017 USD ($)	Mar. 31, 2020 claim	Mar. 31, 2019 claim	Apr. 22, 2016 USD ($)	Jul. 02, 2015 USD ($)	Sep. 17, 2013 USD ($)	Feb. 25, 2013	Feb. 23, 2011 USD ($)	Mar. 23, 2010 USD ($)
Loss Contingencies [Line Items]
Payments for asbestos-related fees and costs, net of insurance recoveries			$ 19,200,000	$ 17,900,000
Current portion of total estimated liability	$ 65,000,000.0		$ 65,000,000.0		$ 65,000,000.0
Asbestos Commitments and Contingencies
Loss Contingencies [Line Items]
Pending claims | claim	28,927	28,851	28,927	28,851	29,056	29,089		29,162	28,498
Court Judgment	$ 23,900,000	$ 40,300,000	$ 23,900,000	$ 40,300,000
Payments for asbestos-related fees and costs, net of insurance recoveries	$ 7,400,000	8,200,000	$ 19,200,000	17,900,000	$ 41,500,000
Cumulative claims resolved | claim	140,000		140,000
Settlement cost	$ 660,000,000		$ 660,000,000
Average settlement cost per resolved claim					15,800	$ 11,300	$ 7,800
Estimated payments to current and future claimants	36,000,000,000		36,000,000,000
Additional liability					255,000,000
Liability for claims	686,000,000		686,000,000		$ 712,000,000
Percentage Of Asbestos Liability Attributable To Settlement And Defense Costs For Future Claims					85.00%
Current portion of total estimated liability	65,000,000		65,000,000
Aggregate value of policy buyout agreements	82,500,000		82,500,000
Estimated Percentage Of Insurance Which Covers Asbestos Costs					14.00%
Insurance reimbursement asset	92,000,000		92,000,000		$ 98,000,000
Gross Settlement And Defense Incurred Costs	$ 11,200,000	$ 13,800,000	$ 23,900,000	$ 40,300,000	$ 66,200,000
Thomas Amato | Asbestos Commitments and Contingencies
Loss Contingencies [Line Items]
Share Of Responsibility Of Verdict													10.00%
James Nelson | Asbestos Commitments and Contingencies
Loss Contingencies [Line Items]
Jury Verdict															$ 14,500,000
Share Of Responsibility Of Verdict															9.09%
Court judgment against all parties held responsible														$ 4,000,000.0
Additional interest on the compensation awarded														$ 10,000.00
Larry Bell | Asbestos Commitments and Contingencies
Loss Contingencies [Line Items]
Share Of Responsibility Of Verdict															5.00%
Frank Vincinguerra | Asbestos Commitments and Contingencies
Loss Contingencies [Line Items]
Share Of Responsibility Of Verdict													20.00%
Richard DeLisle | Asbestos Commitments and Contingencies
Loss Contingencies [Line Items]
Court Judgment												$ 1,300,000
Jury Verdict												$ 8,000,000
Share Of Responsibility Of Verdict												16.00%
James Poage | Asbestos Commitments and Contingencies
Loss Contingencies [Line Items]
Compensatory Damages											$ 1,500,000
Additional Damages											10,000,000
Court Judgment											$ 10,800,000
George Coulbourn | Asbestos Commitments and Contingencies
Loss Contingencies [Line Items]
Additional Damages										$ 5,000,000
Court Judgment										6,800,000
Jury Verdict Total										$ 9,000,000
Share Of Responsibility Of Verdict										20.00%
New York | Asbestos Commitments and Contingencies
Loss Contingencies [Line Items]
Pending claims | claim	18,000		18,000
Mississippi | Asbestos Commitments and Contingencies
Loss Contingencies [Line Items]
Pending claims | claim	300		300
Texas | Asbestos Commitments and Contingencies
Loss Contingencies [Line Items]
Pending claims | claim	100		100
Ohio | Asbestos Commitments and Contingencies
Loss Contingencies [Line Items]
Pending claims | claim	200		200