ACQUISITIONS AND DIVESTITURES - Schedule of preliminary valuation of identifiable assets acquired and liabilities assumed (Details) - USD ($) $ in Millions			6 Months Ended
	Jun. 11, 2019	Feb. 11, 2019	Jul. 31, 2019
Tholu B.V.
Fair value of consideration transferred
Cash consideration	$ 25.1
Deferred payments	29.2
Cash received	(2.1)
Total consideration	52.2
Recognized amounts of identifiable assets acquired and liabilities assumed
Accounts receivable	7.3
Inventories	3.0
Intangibles	24.1
Properties, plants and equipment	6.4
Other assets	1.2
Total assets acquired	42.0
Accounts payable	(4.0)
Capital lease obligations	(1.7)
Long-term deferred tax liability	(5.4)
Other long-term liabilities	(1.0)
Total liabilities assumed	(12.1)
Total identifiable net assets	29.9
Goodwill	$ 22.3
Caraustar
Fair value of consideration transferred
Cash consideration		$ 1,834.9	$ 1,834.9
Cash consideration, measurement period adjustments			0.0
Recognized amounts of identifiable assets acquired and liabilities assumed
Accounts receivable		147.0	147.0
Accounts receivable, measurement period adjustments			0.0
Inventories		103.9	102.7
Inventories, measurement period adjustments			(1.2)
Prepaid and other current assets		21.5	21.0
Prepaid and other current assets, measurement period adjustments			(0.5)
Intangibles		717.1	725.5
Intangibles, measurement period adjustments			8.4
Other long-term assets		1.3	1.8
Other long-term assets, measurement period adjustments			0.5
Properties, plants and equipment		521.3	510.0
Properties, plants and equipment, measurement period adjustments			(11.3)
Total assets acquired		1,512.1	1,508.0
Total assets acquired, measurement period adjustments			(4.1)
Accounts payable		(99.5)	(99.5)
Accounts payable, measurement period adjustments			0.0
Accrued payroll and employee benefits		(42.9)	(42.9)
Accrued payroll and employee benefits, measurement period adjustments			0.0
Other current liabilities		21.8	22.5
Other current liabilities, measurement period adjustments			0.7
Long-term deferred tax liability		(185.7)	(184.9)
Long-term deferred tax liability, measurement period adjustments			(0.8)
Pension and postretirement obligations		(67.1)	(67.1)
Pension and postretirement obligations, measurement period adjustments			0.0
Other long-term liabilities		(12.7)	(25.6)
Other long-term liabilities, measurement period adjustments			12.9
Total liabilities assumed		(429.7)	(442.5)
Total liabilities assumed, measurement period adjustments			12.8
Total identifiable net assets		1,082.4	1,065.5
Total identifiable net assets, measurement period adjustments			(16.9)
Goodwill		$ 752.5	769.4
Goodwill, measurement period adjustments			$ (16.9)