Benefits Expected to be Paid from Plans Assets (Parenthetical) (Detail) - USD ($) $ in Millions	1 Months Ended		12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Jan. 03, 2015
Lump Sums Plan No. 1
Schedule of Pension and Other Postretirement Benefits Expected Benefit Payments [Line Items]
Distributions from existing plan assets	$ 48.4	$ 50.4
Lump Sums Plan No. 2
Schedule of Pension and Other Postretirement Benefits Expected Benefit Payments [Line Items]
Distributions from existing plan assets	$ 2.0		$ 2.0