Employee Benefits - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Severance Costs	$ 0.7	$ 0.8	$ 2.0
Metal and Electrical Engineering Industry Pension Fund
Defined Benefit Plan Disclosure [Line Items]
Actual coverage ratio percentage	97.60%
Western Metal Industry Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Contributions by the Company	14.00%	7.00%
Minimum | Metal and Electrical Engineering Industry Pension Fund
Defined Benefit Plan Disclosure [Line Items]
Required coverage ratio percentage	104.30%
Maximum | Metal and Electrical Engineering Industry Pension Fund
Defined Benefit Plan Disclosure [Line Items]
Contributions by the Company	5.00%	5.00%
Maximum | Other Plans
Defined Benefit Plan Disclosure [Line Items]
Contributions by the Company	5.00%
Defined Benefit Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Accumulated unrecognized actuarial gains and losses	10.00%
Contribution to pension plans	$ 88.9	$ 70.6
Expected pension contributions minimum funding requirements	23.2
Annual benefits expected to be paid year one	88.8
Annual benefits expected to be paid year two	92.1
Annual benefits expected to be paid year three	99.0
Annual benefits expected to be paid year four	105.7
Annual benefits expected to be paid year five	111.5
Annual benefits expected to be paid for the five years thereafter	642.0
Unrecognized actuarial loss amount in accumulated other comprehensive loss expected to be amortized next year	17.5
Unrecognized prior service cost amount in accumulated other comprehensive loss expected to be amortized next year	1.4
Accumulated benefit obligation for all pension plans of the Company	2,356.2	$ 2,492.4
Defined Benefit Pension Plans | Minimum
Defined Benefit Plan Disclosure [Line Items]
Expected pension contributions by the company to the pension plans in the next year	70.0
Defined Benefit Pension Plans | Maximum
Defined Benefit Plan Disclosure [Line Items]
Expected pension contributions by the company to the pension plans in the next year	$ 100.0
Defined Contribution Plans
Defined Benefit Plan Disclosure [Line Items]
Percentage match for base wages	5.00%	5.00%	5.00%
Defined contribution benefit plans expense	$ 45.3	$ 37.9	$ 34.1