Discontinued Operations - Schedule of Financial Results of Discontinued Operations (Parenthetical) (Detail) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Loss on debt extinguishment	$ 10.8	$ 32.4	$ 20.1
Donnelley Financial Solutions And L S C Communications | Discontinued Operations Spinoff
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Spinoff transaction costs				$ 81.2
Loss on debt extinguishment				96.1
Donnelley Financial Solutions And L S C Communications | Discontinued Operations Spinoff | Corporate Level Debt
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Interest expense				55.9
Loss on debt extinguishment				$ 96.1