Restructuring, Impairment and Other - Schedule of Net Restructuring, Impairment and Other Expenses (Income) (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Restructuring Cost And Reserve [Line Items]
Employee Terminations	$ 8.1	$ 8.1
Other Restructuring Charges	4.2	8.2
Multi-Employer Pension Plan Charges	0.7	0.7
Impairment and Other	18.9	0.1
Total	31.9	17.1
Total Operating Segments | Business Services
Restructuring Cost And Reserve [Line Items]
Employee Terminations	5.8	7.8
Other Restructuring Charges	1.1	4.7
Multi-Employer Pension Plan Charges	0.6	0.6
Impairment and Other	18.9	0.1
Total	26.4	13.2
Total Operating Segments | Marketing Solutions
Restructuring Cost And Reserve [Line Items]
Employee Terminations	0.4	0.1
Other Restructuring Charges	0.0
Multi-Employer Pension Plan Charges	0.1	0.1
Impairment and Other	0.0
Total	0.5	0.2
Corporate
Restructuring Cost And Reserve [Line Items]
Employee Terminations	1.9	0.2
Other Restructuring Charges	3.1	3.5
Multi-Employer Pension Plan Charges	0.0
Impairment and Other	0.0
Total	$ 5.0	$ 3.7