Multi-employer Plans (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Multiemployer Plans [Line Items]
COMPANY CONTRIBUTIONS	$ 27.2	$ 25.3	$ 26.0
Metal and Electrical Engineering Industry Pension Fund
Multiemployer Plans [Line Items]
PENSION PLAN NUMBER	135668
COMPANY CONTRIBUTIONS	$ 25.0	23.1	23.0
Western Metal Industry Pension Plan
Multiemployer Plans [Line Items]
PENSION PLAN NUMBER	1
EIN	916033499
COMPANY CONTRIBUTIONS	$ 1.4	1.5	2.1
Other Plans
Multiemployer Plans [Line Items]
COMPANY CONTRIBUTIONS	$ 0.8	$ 0.7	$ 0.9