Employee Benefits - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Severance Costs	$ 2.0	$ 3.3	$ 1.8
Defined Benefit Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Accumulated unrecognized actuarial gains and losses	10.00%
Contribution to pension plans	$ 185.7	62.9
Expected pension contributions minimum funding requirements	17.1
Annual benefits expected to be paid year one	80.7
Annual benefits expected to be paid year two	82.7
Annual benefits expected to be paid year three	87.4
Annual benefits expected to be paid year four	93.5
Annual benefits expected to be paid year five	99.2
Annual benefits expected to be paid for the five years thereafter	576.3
Retirement plan, total lump-sum distribution	48.5
Unrecognized actuarial loss amount in accumulated other comprehensive loss expected to be amortized next year	27.1
Unrecognized prior service cost amount in accumulated other comprehensive loss expected to be amortized next year	1.2
Accumulated benefit obligation for all pension plans of the Company	2,215.3	$ 2,028.2
Estimated Decrease in Pension Expense for 2017 due to change of method used to estimate service cost and interest cost components of pension expense from a single weighted-average method to an individual spot rate approach	$ 15.0
Metal and Electrical Engineering Industry Pension Fund
Defined Benefit Plan Disclosure [Line Items]
Actual coverage ratio percentage	96.20%
Western Metal Industry Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Contributions by the Company	15.00%	12.00%
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	$ 34.1	$ 36.1	$ 36.3
Minimum | Defined Benefit Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Expected pension contributions by the company to the pension plans in the next year	$ 50.0
Minimum | Metal and Electrical Engineering Industry Pension Fund
Defined Benefit Plan Disclosure [Line Items]
Required coverage ratio percentage	104.30%
Maximum | Defined Benefit Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Expected pension contributions by the company to the pension plans in the next year	$ 100.0
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%