Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Statement [Abstract]
Net Sales	$ 1,697.7	$ 1,581.6	$ 4,907.8	$ 4,640.3
Cost of Sales	1,442.2	1,315.2	4,069.4	3,820.0
Selling, General and Administrative	126.3	131.3	394.1	387.8
Other Expense, Net	1.1	4.2	2.2	7.1
Business Combinations and Shutdown and Other Special Charges, Net	9.0	8.2	48.2	24.3
Income from Operations	119.1	122.7	393.9	401.1
Nonoperating Pension and Postretirement Benefit Income (Expense)	0.2	0.0	(150.8)	(0.1)
Interest Expense, Net	(32.0)	(35.9)	(96.4)	(106.4)
Income before Income Taxes and Equity Income of Unconsolidated Entity	87.3	86.8	146.7	294.6
Income Tax Expense	(8.3)	(16.9)	(21.2)	(60.9)
Income before Equity Income of Unconsolidated Entity	79.0	69.9	125.5	233.7
Equity Income of Unconsolidated Entity	0.3	0.1	0.7	0.5
Net Income	79.3	70.0	126.2	234.2
Net Income Attributable to Noncontrolling Interest	(15.6)	(17.9)	(23.1)	(60.4)
Net Income Attributable to Graphic Packaging Holding Company	$ 63.7	$ 52.1	$ 103.1	$ 173.8
Net Income Per Share Attributable to Graphic Packaging Holding Company — Basic (in dollars per share)	$ 0.23	$ 0.18	$ 0.37	$ 0.59
Net Income Per Share Attributable to Graphic Packaging Holding Company — Diluted (in dollars per share)	$ 0.23	$ 0.18	$ 0.36	$ 0.59