Restructuring and Other - Schedule of Net Restructuring and Other Expenses (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Restructuring Cost And Reserve [Line Items]
Employee Terminations	$ 5.2	$ 2.4	$ 8.4	$ 8.8
Other Restructuring Charges	3.8	1.1	5.4	2.7
Total Restructuring Charges	9.0	3.5	13.8	11.5
Other	1.4	(0.3)	(3.2)	0.2
Multi-Employer Pension Plan Charges	0.6	0.6	1.2	1.2
Total	11.0	3.8	11.8	12.9
Total Operating Segments | Business Services
Restructuring Cost And Reserve [Line Items]
Employee Terminations	4.3	1.6	6.1	5.4
Other Restructuring Charges	1.1	1.1	2.1	2.2
Total Restructuring Charges	5.4	2.7	8.2	7.6
Other	0.2	(0.3)	(4.7)	(0.3)
Multi-Employer Pension Plan Charges	0.5	0.5	1.0	1.0
Total	6.1	2.9	4.5	8.3
Total Operating Segments | Marketing Solutions
Restructuring Cost And Reserve [Line Items]
Employee Terminations	0.7	0.1	1.8	1.2
Other Restructuring Charges		(0.1)		0.3
Total Restructuring Charges	0.7		1.8	1.5
Other	1.2		1.5	0.5
Multi-Employer Pension Plan Charges	0.1	0.1	0.2	0.2
Total	2.0	0.1	3.5	2.2
Corporate
Restructuring Cost And Reserve [Line Items]
Employee Terminations	0.2	0.7	0.5	2.2
Other Restructuring Charges	2.7	0.1	3.3	0.2
Total Restructuring Charges	2.9	0.8	3.8	2.4
Total	$ 2.9	$ 0.8	$ 3.8	$ 2.4