New Accounting Pronouncements - Narrative (Detail) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2020	Jan. 01, 2020	Dec. 31, 2019
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Cumulative impact of adopting ASU, net of tax	$ (2,418.3)		$ (2,336.8)
Change in Accounting Principle, Accounting Standards Update, Adopted [true false]	true
Change in Accounting Principle, Accounting Standards Update, Adoption Date	Jan. 01, 2020
Change in Accounting Principle, Accounting Standards Update, Transition Option Elected [Extensible List]	rrd:AccountingStandardsUpdate201613RetrospectiveMember
Accounting Standards Update 2016-13 | Cumulative Effect Period of Adoption Adjustment | Revision of Prior Period Adjustment
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Cumulative impact of adopting ASU, net of tax		$ 0.3