Commitments and Contingencies - Activity Related to Asbestos Claims (Detail) - Asbestos Related Matters [Member] - Claim Claim in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Number of Pending Claims [Roll Forward]
Pending claims - Beginning	24	24	26
New claims	4	4	4
Settlements	(1)	(1)	(1)
Dismissals	(2)	(3)	(5)
Pending claims - Ending	25	24	24

The total number of new claims filed pertaining to a loss contingency during the period.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118942415&loc=d3e14435-108349

Name:	us-gaap_LossContingencyNewClaimsFiledNumber
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration