Restructuring, Impairment and Other Charges - Schedule of Net Restructuring, Impairment and Other Charges (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Restructuring Cost And Reserve [Line Items]
Employee Terminations	$ 23.5	$ 21.9	$ 22.4
Other Restructuring Charges	4.8	3.5	9.2
Total Restructuring Charges	28.3	25.4	31.6
Impairment	22.4	556.6	28.9
Other Charges	2.3	2.3	2.2
Total	53.0	584.3	62.7
Total Operating Segments | Variable Print
Restructuring Cost And Reserve [Line Items]
Employee Terminations	4.2	1.4	3.1
Other Restructuring Charges	1.1	1.7	4.7
Total Restructuring Charges	5.3	3.1	7.8
Impairment		557.9	(0.5)
Other Charges	1.9	1.9	1.8
Total	7.2	562.9	9.1
Total Operating Segments | Strategic Services
Restructuring Cost And Reserve [Line Items]
Employee Terminations	2.6	1.8	4.4
Other Restructuring Charges	0.3	(0.1)	0.1
Total Restructuring Charges	2.9	1.7	4.5
Impairment	21.9		0.9
Other Charges	0.4	0.4	0.4
Total	25.2	2.1	5.8
Total Operating Segments | International
Restructuring Cost And Reserve [Line Items]
Employee Terminations	8.0	9.6	11.9
Other Restructuring Charges	2.6	1.8	3.2
Total Restructuring Charges	10.6	11.4	15.1
Impairment	0.1	(2.5)	28.5
Total	10.7	8.9	43.6
Corporate
Restructuring Cost And Reserve [Line Items]
Employee Terminations	8.7	9.1	3.0
Other Restructuring Charges	0.8	0.1	1.2
Total Restructuring Charges	9.5	9.2	4.2
Impairment	0.4	1.2
Total	$ 9.9	$ 10.4	$ 4.2