Revenue Recognition - Net Sales Disaggregated by Product Line (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Disaggregation Of Revenue [Line Items]
Total net sales	$ 1,191.3	$ 1,417.2	$ 3,417.7	$ 4,044.0
Commercial Print
Disaggregation Of Revenue [Line Items]
Total net sales	347.7	442.9	986.6	1,278.8
Packaging
Disaggregation Of Revenue [Line Items]
Total net sales	193.6	182.1	459.1	484.2
Direct Marketing
Disaggregation Of Revenue [Line Items]
Total net sales	125.9	193.5	416.8	479.0
Labels
Disaggregation Of Revenue [Line Items]
Total net sales	124.7	123.9	359.9	364.1
Digital Print and Fulfillment
Disaggregation Of Revenue [Line Items]
Total net sales	104.4	122.5	302.6	347.2
Statements
Disaggregation Of Revenue [Line Items]
Total net sales	104.3	134.0	333.1	417.1
Supply Chain Management
Disaggregation Of Revenue [Line Items]
Total net sales	77.4	69.8	212.0	222.4
Forms
Disaggregation Of Revenue [Line Items]
Total net sales	48.2	60.0	149.2	181.6
Business Process Outsourcing
Disaggregation Of Revenue [Line Items]
Total net sales	40.9	61.1	125.5	189.3
Digital and Creative Solutions
Disaggregation Of Revenue [Line Items]
Total net sales	$ 24.2	$ 27.4	$ 72.9	$ 80.3