Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Contingencies And Commitments [Line Items]
Operating lease obligation expiration period			2031
Rental expense for operating leases			$ 16.6	$ 14.8	$ 13.6
Sublease income			0.5	0.5	$ 0.9
Assets recorded under capital leases, net	$ 8.5	$ 6.6	8.5	6.6
Assets recorded under capital leases, accumulated amortization	2.9	2.3	2.9	2.3
Accrual for reasonably estimable remediation cost	3.3		3.3
Amount paid to implement remedial action work plan				5.1
PrimeSource [Member]
Contingencies And Commitments [Line Items]
Litigation settlement and expenses			$ 3.5	$ 3.1
Discontinued Operations [Member]
Contingencies And Commitments [Line Items]
Accrual charge after remaining estimate of costs to complete remediation	$ 0.5	$ 1.5