Retirement Plans and Other Post-Retirement Benefits - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation for all defined benefit pension plans	$ 526.7	$ 553.8
Defined contribution plans Employees contribution	50.00%
Expense associated with Defined Contribution Plans	$ 2.1	$ 2.0	$ 1.9
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rates	4.65%	4.21%
Prior service cost as a component of net periodic benefit cost from accumulated other comprehensive income (loss)	$ 2.7
Actuarial net (gain) loss as a component of net periodic benefit cost from accumulated other comprehensive income (loss)	$ 0.2
Pension Benefits [Member] | Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rates	2.30%
Pension Benefits [Member] | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rates	4.77%
Other Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rates	4.38%	3.89%
Prior service cost as a component of net periodic benefit cost from accumulated other comprehensive income (loss)		$ 12.2
Actuarial net (gain) loss as a component of net periodic benefit cost from accumulated other comprehensive income (loss)		$ 0.2
Other Benefits [Member] | Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rates	4.14%
Other Benefits [Member] | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rates	4.43%