Commitments and Contingencies - Narrative (Detail) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2021 USD ($) Facility	Sep. 30, 2021 USD ($) Facility	Dec. 31, 2020 USD ($)
Commitment And Contingencies [Line Items]
Number of sites cited as potentially responsible party | Facility	4	4
Number of previously and currently owned sites with potential remediation obligations | Facility	6	6
Gain on settlement of multiemployer pension plan obligation		$ 2.2
Cash payments related to settlement of two multiemployer pension plans	$ 18.4
Multiemployer pension plan, accrued amount of estimate share of remaining liability	13.7	13.7
Donnelley Financial Solutions, Inc.
Commitment And Contingencies [Line Items]
Potential contingent obligations	1.4	1.4
LSC Communications, Inc.
Commitment And Contingencies [Line Items]
Potential contingent obligations	34.9	34.9
Multi-employer pension plan obligation	$ 100.0	$ 100.0
Multi-employer pension plan obligation payment period		13 years
Multi-employer pension plan, present value of estimated future payments			$ 37.1