Income Taxes - Reconciliation of Income Tax Expense at U.S. Federal Statutory Tax Rate (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Effective Income Tax Rate Continuing Operations Tax Rate Reconciliation [Abstract]
Income taxes at the U.S. federal statutory tax rate	$ 10.3	$ (3.3)	$ 10.6
Change in valuation allowances	(3.2)	(3.7)	8.1
Interest limitation valuation allowance	18.8	(8.0)	27.8
State and local income taxes, net of U.S. federal income tax benefit	5.5	4.7	(7.3)
Foreign tax	2.9	(2.1)	5.1
Adjustment of uncertain tax positions and interest	(5.6)	1.1	(0.6)
Foreign tax rate differential	(0.3)	(0.8)	(0.5)
Tax impact of net gain on sale of Donnelley Financial and LSC shares			0.5
Global intangible low-taxed income	5.0	3.5	5.2
Corporate owned life insurance policies		17.3
Non-deductible compensation	9.1
Other	2.4	1.3	6.0
Total	$ 44.9	$ 10.0	$ 54.9