Guarantor Consolidating Financial Statements - Condensed Consolidating Statements of Operations (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Condensed Financial Statements, Captions [Line Items]
Net Sales	$ 1,519.8	$ 1,581.6	$ 1,552.8	$ 1,505.9	$ 1,509.3	$ 1,531.8	$ 1,510.9	$ 1,477.4	$ 6,160.1	$ 6,029.4	$ 4,405.6
Cost of Sales									5,067.5	5,077.0	3,696.1
Selling, General and Administrative									511.9	471.8	347.5
Other Expense, Net									9.2	7.2	3.0
Business Combinations and Shutdown and Other Special Charges, Net									37.9	14.9	31.1
Income from Operations	132.1	122.9	144.4	134.2	107.6	166.6	110.1	74.2	533.6	458.5	327.9
Nonoperating Pension and Postretirement Benefit (Expense) Income									(39.5)	14.9	14.8
Interest Expense, Net									(140.6)	(123.7)	(89.7)
Loss on Modification or Extinguishment of Debt									0.0	(1.9)	0.0
Income before Income Taxes and Equity Income of Unconsolidated Entity									353.5	347.8	253.0
Income Tax Expense									(20.4)	(11.8)	321.7
Income before Equity Income of Unconsolidated Entities									333.1	336.0	574.7
Equity Income of Unconsolidated Entity									0.4	1.2	1.7
Equity in Net Earnings of Subsidiaries									0.0	0.0	0.0
Net Income	$ 50.3	$ 83.5	$ 104.4	$ 95.3	$ 75.3	$ 135.4	$ 81.2	$ 45.3	333.5	337.2	576.4
Comprehensive Income (Loss)									$ 350.6	278.7	625.2
Graphic Packaging International Limited Liability Partnership
Condensed Financial Statements, Captions [Line Items]
Parent's ownership percentage									100.00%
Reportable Legal Entities | Issuer
Condensed Financial Statements, Captions [Line Items]
Net Sales									$ 5,176.4	5,010.0	3,510.0
Cost of Sales									4,281.9	4,223.9	2,945.9
Selling, General and Administrative									417.9	376.7	261.3
Other Expense, Net									1.7	(2.5)	(6.1)
Business Combinations and Shutdown and Other Special Charges, Net									18.3	14.4	19.4
Income from Operations									456.6	397.5	289.5
Nonoperating Pension and Postretirement Benefit (Expense) Income									(41.6)	11.4	14.8
Interest Expense, Net									(135.1)	(117.9)	(84.9)
Loss on Modification or Extinguishment of Debt										(1.9)
Income before Income Taxes and Equity Income of Unconsolidated Entity									279.9	289.1	219.4
Income Tax Expense									(2.4)	(1.6)	331.1
Income before Equity Income of Unconsolidated Entities									277.5	287.5	550.5
Equity Income of Unconsolidated Entity									0.0	0.0	0.0
Equity in Net Earnings of Subsidiaries									56.0	49.7	25.9
Net Income									333.5	337.2	576.4
Comprehensive Income (Loss)									350.6	278.7	625.2
Reportable Legal Entities | Combined Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Net Sales									0.0	0.0	48.5
Cost of Sales									(1.2)	(1.1)	40.7
Selling, General and Administrative									(2.4)	(2.7)	1.4
Other Expense, Net									0.0	0.0	0.1
Business Combinations and Shutdown and Other Special Charges, Net									0.0	0.0	0.0
Income from Operations									3.6	3.8	6.3
Nonoperating Pension and Postretirement Benefit (Expense) Income									0.0	0.0	0.0
Interest Expense, Net									0.0	0.0	0.0
Loss on Modification or Extinguishment of Debt										0.0
Income before Income Taxes and Equity Income of Unconsolidated Entity									3.6	3.8	6.3
Income Tax Expense									(0.1)	(0.1)	(3.5)
Income before Equity Income of Unconsolidated Entities									3.5	3.7	2.8
Equity Income of Unconsolidated Entity									0.0	0.0	0.0
Equity in Net Earnings of Subsidiaries									(3.5)	(3.7)	(6.1)
Net Income									0.0	0.0	(3.3)
Comprehensive Income (Loss)									1.1	0.1	(26.0)
Reportable Legal Entities | Combined Nonguarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Net Sales									1,414.5	1,365.2	1,169.6
Cost of Sales									1,217.6	1,200.0	1,032.0
Selling, General and Administrative									96.4	97.8	84.8
Other Expense, Net									7.5	9.7	9.0
Business Combinations and Shutdown and Other Special Charges, Net									19.6	0.5	11.7
Income from Operations									73.4	57.2	32.1
Nonoperating Pension and Postretirement Benefit (Expense) Income									2.1	3.5	0.0
Interest Expense, Net									(5.5)	(5.8)	(4.8)
Loss on Modification or Extinguishment of Debt										0.0
Income before Income Taxes and Equity Income of Unconsolidated Entity									70.0	54.9	27.3
Income Tax Expense									(17.9)	(10.1)	(5.9)
Income before Equity Income of Unconsolidated Entities									52.1	44.8	21.4
Equity Income of Unconsolidated Entity									0.4	1.2	1.7
Equity in Net Earnings of Subsidiaries									0.0	0.0	0.0
Net Income									52.5	46.0	23.1
Comprehensive Income (Loss)									71.0	(2.8)	78.5
Consolidating Eliminations
Condensed Financial Statements, Captions [Line Items]
Net Sales									(430.8)	(345.8)	(322.5)
Cost of Sales									(430.8)	(345.8)	(322.5)
Selling, General and Administrative									0.0	0.0	0.0
Other Expense, Net									0.0	0.0	0.0
Business Combinations and Shutdown and Other Special Charges, Net									0.0	0.0	0.0
Income from Operations									0.0	0.0	0.0
Nonoperating Pension and Postretirement Benefit (Expense) Income									0.0	0.0	0.0
Interest Expense, Net									0.0	0.0	0.0
Loss on Modification or Extinguishment of Debt										0.0
Income before Income Taxes and Equity Income of Unconsolidated Entity									0.0	0.0	0.0
Income Tax Expense									0.0	0.0	0.0
Income before Equity Income of Unconsolidated Entities									0.0	0.0	0.0
Equity Income of Unconsolidated Entity									0.0	0.0	0.0
Equity in Net Earnings of Subsidiaries									(52.5)	(46.0)	(19.8)
Net Income									(52.5)	(46.0)	(19.8)
Comprehensive Income (Loss)									$ (72.1)	$ 2.7	$ (52.5)