Multi-employer Plans (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Multiemployer Plans [Line Items]
COMPANY CONTRIBUTIONS	$ 31.8	$ 27.2	$ 25.3
Metal and Electrical Engineering Industry Pension Fund
Multiemployer Plans [Line Items]
PENSION PLAN NUMBER	135668
COMPANY CONTRIBUTIONS	$ 27.9	25.0	23.1
Western Metal Industry Pension Plan
Multiemployer Plans [Line Items]
PENSION PLAN NUMBER	1
EIN	916033499
COMPANY CONTRIBUTIONS	$ 2.7	1.4	1.5
Other Plans
Multiemployer Plans [Line Items]
COMPANY CONTRIBUTIONS	$ 1.2	$ 0.8	$ 0.7

Amount of contributions made to multiemployer plan by employer.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 80
-Section 50
-Paragraph 9
-URI http://asc.fasb.org/extlink&oid=65877416&loc=SL14450691-114947

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 80
-Section 50
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=65877416&loc=SL14450702-114947

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 80
-Section 50
-Paragraph 5
-Subparagraph (e)(1)
-URI http://asc.fasb.org/extlink&oid=65877416&loc=SL14450657-114947

Name:	us-gaap_MultiemployerPlanContributionsByEmployer
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration