Restructuring, Impairment and Other Charges - Schedule of Net Restructuring, Impairment and Other Charges (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Restructuring Cost And Reserve [Line Items]
Employee Terminations	$ 22.3	$ 12.9	$ 23.5
Other Restructuring Charges	16.6	15.9	4.1
Impairment and Other	93.5	7.0	22.4
Multi-Employer Pension Plan Charges	2.9	3.0	3.0
Total	135.3	38.8	53.0
Total Operating Segments | Business Services
Restructuring Cost And Reserve [Line Items]
Employee Terminations	20.2	10.1	12.1
Other Restructuring Charges	7.4	8.3	3.0
Impairment and Other	93.5	4.8	0.1
Multi-Employer Pension Plan Charges	2.5	2.6	2.6
Total	123.6	25.8	17.8
Total Operating Segments | Marketing Solutions
Restructuring Cost And Reserve [Line Items]
Employee Terminations	0.5	2.0	2.7
Other Restructuring Charges	0.1		0.3
Impairment and Other		1.5	21.9
Multi-Employer Pension Plan Charges	0.4	0.4	0.4
Total	1.0	3.9	25.3
Corporate
Restructuring Cost And Reserve [Line Items]
Employee Terminations	1.6	0.8	8.7
Other Restructuring Charges	9.1	7.6	0.8
Impairment and Other		0.7	0.4
Total	$ 10.7	$ 9.1	$ 9.9