Asset Retirement Obligations - Changes to Asset Retirement Obligation (Parenthetical) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020
Asset Retirement Obligation [Abstract]
Revisions in estimated cash flows adjustment	$ 4.2	$ 4.5

Asset retirement obligation revision of estimate adjustment.

No definition available.

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Namespace Prefix:	pkg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration