Profit Sharing, Retirement Savings Plans and Defined Benefit Pension Plans - Narrative (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Provisions charged from operations for the profit sharing plan and retirement savings plans	$ 36.3	$ 39.9	$ 42.9
Contribution of common stock to profit sharing plan (in shares)	538,524	502,519	830,600
Defined benefit pension plan corridor rate	10.00%
Percentage of equity allocation, maximum	65.00%
Percentage of fixed income allocation, minimum	35.00%
Plan assets	$ 668.7	$ 776.2	$ 771.8
Expected benefits paid	39.9
Bulk Annuity Contract [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	$ 112.0
Minimum | Equity Security
Defined Benefit Plan Disclosure [Line Items]
Investment target asset allocation	40.00%
Minimum | Fixed Income Securities
Defined Benefit Plan Disclosure [Line Items]
Investment target asset allocation	50.00%
Maximum | Equity Security
Defined Benefit Plan Disclosure [Line Items]
Investment target asset allocation	50.00%
Maximum | Fixed Income Securities
Defined Benefit Plan Disclosure [Line Items]
Investment target asset allocation	60.00%
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Expected contribution	$ 17.0
Expected benefits paid	$ 3.0