Restructuring and Other - Schedule of Net Restructuring and Other Expenses (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Restructuring Cost And Reserve [Line Items]
Employee Terminations	$ 2.8	$ 10.7	$ 11.2	$ 19.5
Other Restructuring Charges	6.6	1.1	12.0	3.8
Total Restructuring Charges	9.4	11.8	23.2	23.3
Other	1.1	21.5	(2.1)	21.7
Multi-Employer Pension Plan Charges	0.5	0.5	1.7	1.7
Total	11.0	33.8	22.8	46.7
Total Operating Segments | Business Services
Restructuring Cost And Reserve [Line Items]
Employee Terminations	2.7	4.2	8.8	9.6
Other Restructuring Charges	3.6	0.9	5.7	3.1
Total Restructuring Charges	6.3	5.1	14.5	12.7
Other	0.4	0.2	(4.3)	(0.1)
Multi-Employer Pension Plan Charges	0.4	0.4	1.4	1.4
Total	7.1	5.7	11.6	14.0
Total Operating Segments | Marketing Solutions
Restructuring Cost And Reserve [Line Items]
Employee Terminations	0.1	1.4	1.9	2.6
Other Restructuring Charges				0.3
Total Restructuring Charges	0.1	1.4	1.9	2.9
Other		21.3	1.5	21.8
Multi-Employer Pension Plan Charges	0.1	0.1	0.3	0.3
Total	0.2	22.8	3.7	25.0
Corporate
Restructuring Cost And Reserve [Line Items]
Employee Terminations		5.1	0.5	7.3
Other Restructuring Charges	3.0	0.2	6.3	0.4
Total Restructuring Charges	3.0	5.3	6.8	7.7
Other	0.7		0.7
Total	$ 3.7	$ 5.3	$ 7.5	$ 7.7