Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
CASH FLOWS FROM OPERATING ACTIVITIES:
Net Income	$ 70.0	$ 122.0	$ 234.2	$ 230.7
Adjustments to Reconcile Net Income to Net Cash Used in Operating Activities:
Depreciation and Amortization	110.5	110.7	337.8	331.8
Deferred Income Taxes			34.0	19.9
Amount of Postretirement Expense Greater (Less) Than Funding			0.6	(2.5)
Gain on the Sale of Assets			0.0	(38.6)
Other, Net			18.4	31.5
Changes in Operating Assets and Liabilities			(324.3)	(872.8)
Net Cash Provided by (Used in) Operating Activities			300.7	(300.0)
CASH FLOWS FROM INVESTING ACTIVITIES:
Capital Spending			(213.1)	(258.6)
Packaging Machinery Spending			(16.8)	(11.4)
Acquisition of Businesses, Net of Cash Acquired			(52.9)	(89.0)
Proceeds Received from the Sale of Assets, Net of Selling Costs			0.0	49.4
Beneficial Interest on Sold Receivables			320.3	902.8
Beneficial Interest Obtained in Exchange for Proceeds			(155.4)	(226.9)
Other, Net			(3.5)	(6.0)
Net Cash (Used in) Provided by Investing Activities			(121.4)	360.3
CASH FLOWS FROM FINANCING ACTIVITIES:
Repurchase of Common Stock			(128.8)	0.0
Payments on Debt			(27.4)	(143.3)
Proceeds from Issuance of Debt			300.0	0.0
Borrowings under Revolving Credit Facilities			1,970.7	1,297.5
Payments on Revolving Credit Facilities			(2,216.0)	(1,148.5)
Repurchase of Common Stock related to Share-Based Payments			(4.1)	(4.1)
Debt Issuance Costs			(5.0)	(7.9)
Dividends and Distributions Paid to GPIP Partner			(87.0)	(82.1)
Other, Net			(3.2)	1.2
Net Cash Used in Financing Activities			(200.8)	(87.2)
Effect of Exchange Rate Changes on Cash			(0.3)	(0.8)
Net Decrease in Cash and Cash Equivalents			(21.8)	(27.7)
Cash and Cash Equivalents at Beginning of Period			70.5	67.4	$ 67.4
CASH AND CASH EQUIVALENTS AT END OF PERIOD	$ 48.7	$ 39.7	48.7	39.7	$ 70.5
Non-cash Investing Activities:
Beneficial Interest (Sold) in Exchange for Trade receivables			(91.7)
Beneficial Interest Obtained in Exchange for Trade Receivables				874.6
Non-cash Investment in NACP Combination			0.0	1,235.7
Non-cash Investing Activities			(91.7)	2,110.3
Non-cash Financing Activities:
Non-cash Financing of NACP Combination			0.0	660.0
Non-Cash Financing Activities			$ 0.0	$ 660.0