Segment Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Segment Reporting Information [Line Items]
Net sales	$ 1,584.0	$ 1,417.4	$ 3,120.5	$ 2,818.4
Operating income (loss)	233.8	200.2	436.9	381.0
Interest expense, net	(25.2)	(22.5)	(49.2)	(44.1)
Income before taxes	208.6	177.7	387.7	336.9
Intersegment Eliminations
Segment Reporting Information [Line Items]
Net sales	(37.1)	(34.7)	(70.9)	(72.4)
Segment Reconciling Items
Segment Reporting Information [Line Items]
Net sales	(37.1)	(34.7)	(70.9)	(72.4)
Packaging
Segment Reporting Information [Line Items]
Net sales	1,305.5	1,123.6	2,556.8	2,217.4
Operating income (loss)	224.5	192.4	415.3	353.9
Packaging | Intersegment Eliminations
Segment Reporting Information [Line Items]
Net sales	6.0	1.7	11.6	3.4
Packaging | Operating Segments
Segment Reporting Information [Line Items]
Net sales	1,311.5	1,125.3	2,568.4	2,220.8
Paper
Segment Reporting Information [Line Items]
Net sales	253.7	266.8	512.9	547.3
Operating income (loss)	29.1	24.4	58.9	60.5
Paper | Operating Segments
Segment Reporting Information [Line Items]
Net sales	253.7	266.8	512.9	547.3
Corporate and Other Segment
Segment Reporting Information [Line Items]
Net sales	24.8	27.0	50.8	53.7
Operating income (loss)	(19.8)	(16.6)	(37.3)	(33.4)
Corporate and Other Segment | Intersegment Eliminations
Segment Reporting Information [Line Items]
Net sales	31.1	33.0	59.3	69.0
Corporate and Other Segment | Operating Segments
Segment Reporting Information [Line Items]
Net sales	$ 55.9	$ 60.0	$ 110.1	$ 122.7