Restructuring, Impairment and Other Charges - Schedule of Net Restructuring, Impairment and Other Charges (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Restructuring Cost And Reserve [Line Items]
Employee Terminations	$ 10.7	$ 9.7	$ 19.5	$ 20.7
Other Restructuring Charges	1.1	0.6	3.8	2.9
Total Restructuring Charges	11.8	10.3	23.3	23.6
Impairment	21.5	(0.1)	21.7	(1.0)
Other Charges	0.5	0.6	1.7	1.7
Total	33.8	10.8	46.7	24.3
Total Operating Segments | Variable Print
Restructuring Cost And Reserve [Line Items]
Employee Terminations	3.0	1.1	4.0	1.5
Other Restructuring Charges	0.6	0.3	0.9	1.5
Total Restructuring Charges	3.6	1.4	4.9	3.0
Impairment	0.2		(0.1)	0.3
Other Charges	0.4	0.5	1.4	1.4
Total	4.2	1.9	6.2	4.7
Total Operating Segments | Strategic Services
Restructuring Cost And Reserve [Line Items]
Employee Terminations	0.7	1.2	1.8	1.7
Other Restructuring Charges			0.3
Total Restructuring Charges	0.7	1.2	2.1	1.7
Impairment	21.3		21.8
Other Charges	0.1	0.1	0.3	0.3
Total	22.1	1.3	24.2	2.0
Total Operating Segments | International
Restructuring Cost And Reserve [Line Items]
Employee Terminations	1.9	0.9	6.4	7.4
Other Restructuring Charges	0.3	0.2	2.2	1.3
Total Restructuring Charges	2.2	1.1	8.6	8.7
Impairment				(2.5)
Total	2.2	1.1	8.6	6.2
Corporate
Restructuring Cost And Reserve [Line Items]
Employee Terminations	5.1	6.5	7.3	10.1
Other Restructuring Charges	0.2	0.1	0.4	0.1
Total Restructuring Charges	5.3	6.6	7.7	10.2
Impairment		(0.1)		1.2
Total	$ 5.3	$ 6.5	$ 7.7	$ 11.4