Restructuring and Other - Schedule of Net Restructuring and Other Expenses (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Restructuring Cost And Reserve [Line Items]
Employee Terminations	$ 10.8	$ 5.2	$ 18.9	$ 8.4
Other Restructuring Charges	4.5	3.7	12.7	5.1
Multi-Employer Pension Plan Charges	0.7	0.7	1.4	1.5
Other	0.0	1.4	0.1	(3.2)
Total	16.0	11.0	33.1	11.8
Total Operating Segments | Business Services
Restructuring Cost And Reserve [Line Items]
Employee Terminations	10.2	4.3	18.0	6.1
Other Restructuring Charges	3.0	1.0	7.7	1.8
Multi-Employer Pension Plan Charges	0.6	0.6	1.2	1.3
Other	0.0	0.2	0.1	(4.7)
Total	13.8	6.1	27.0	4.5
Total Operating Segments | Marketing Solutions
Restructuring Cost And Reserve [Line Items]
Employee Terminations	0.3	0.7	0.4	1.8
Other Restructuring Charges	0.1		0.1
Multi-Employer Pension Plan Charges	0.1	0.1	0.2	0.2
Other	0.0	1.2	0.0	1.5
Total	0.5	2.0	0.7	3.5
Corporate
Restructuring Cost And Reserve [Line Items]
Employee Terminations	0.3	0.2	0.5	0.5
Other Restructuring Charges	1.4	2.7	4.9	3.3
Multi-Employer Pension Plan Charges	0.0		0.0
Other	0.0		0.0
Total	$ 1.7	$ 2.9	$ 5.4	$ 3.8