XML 93 R77.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Employee Benefit Plans and Other Postretirement Benefits - Components of Net Periodic Benefit Cost and Other Comprehensive (Income) Loss (Parenthetical) (Details) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2018 USD ($)
Defined Benefit Plan Disclosure [Line Items] |
Accumulated losses, excess percentage threshold required on projected benefit obligation | 10.00%
Estimated net periodic benefit cost for 2019 | $ 12.7
Packaging Corporation of America | Minimum |
Defined Benefit Plan Disclosure [Line Items] |
Average remaining service period of active employees used for recognition of market-related value of assets | 7 years
Packaging Corporation of America | Maximum |
Defined Benefit Plan Disclosure [Line Items] |
Average remaining service period of active employees used for recognition of market-related value of assets | 10 years
Boise Inc. | Minimum |
Defined Benefit Plan Disclosure [Line Items] |
Average remaining lifetime of inactive participants used for recognition of market-related value of assets | 24 years
Boise Inc. | Maximum |
Defined Benefit Plan Disclosure [Line Items] |
Average remaining lifetime of inactive participants used for recognition of market-related value of assets | 27 years

X
- Definition Accumulated losses, excess percentage threshold required on projected benefit obligation. + References No definition available. + Details
Name: | pkg_AccumulatedLossesExcessPercentageThresholdRequiredOnProjectedBenefitObligation
Namespace Prefix: | pkg_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Average remaining lifetime of inactive participants used for recognition of market-related value of assets. + References No definition available. + Details
Name: | pkg_AverageRemainingLifetimeOfInactiveParticipantsUsedForRecognitionOfMarketRelatedValueOfAssets
Namespace Prefix: | pkg_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Average remaining service period of active employees used for recognition of market-related value of assets. + References No definition available. + Details
Name: | pkg_AverageRemainingServicePeriodOfActiveEmployeesUsedForRecognitionOfMarketRelatedValueOfAssets
Namespace Prefix: | pkg_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_DefinedBenefitPlanDisclosureLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount included in accumulated other comprehensive (income) loss for prior service cost (credit) expected to be recognized in net periodic benefit cost (credit) for fiscal year following most recent annual statement of financial position. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (s) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanExpectedAmortizationOfPriorServiceCostCreditNextFiscalYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | dei_LegalEntityAxis=pkg_PackagingCorporationOfAmericaMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=pkg_BoiseIncMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |