XML 69 R58.htm IDEA: XBRL DOCUMENT
v3.21.2

Cash, Cash Equivalents, and Marketable Debt Securities - Schedule of Company's Cash and Available-For-Sale (AFS) Debt Securities by Major Asset Category (Details) - USD ($) $ in Millions | 9 Months Ended | 12 Months Ended
--- | --- | ---
Sep. 30, 2021 | Dec. 31, 2020
Financial Instruments [Line Items] |  |  |  |
Adjusted Cost Basis |  | $ 1,848.9 | [1] | $ 1,122.4
Unrealized Gain |  | 0.1 | [1] | 0.5
Unrealized Loss |  | 0.0 | [1] | 0.0
Fair Value |  | 1,849.0 | [1] | 1,122.9
Cash and cash equivalents |  | 1,702.9 | [1] | 974.6
Short-term marketable debt securities |  | 88.3 | [1] | 105.6
Long-term marketable debt securities |  | 57.8 | [1] | 42.7
Level 1 |  |  |  |
Financial Instruments [Line Items] |  |  |  |
Adjusted Cost Basis | [2] | 34.6 |  | 28.7
Unrealized Gain | [2] | 0.0 |  | 0.2
Unrealized Loss | [2] | 0.0 |  | 0.0
Fair Value | [2] | 34.6 |  | 28.9
Cash and cash equivalents | [2] | 7.0 |  | 0.6
Short-term marketable debt securities | [2] | 19.3 |  | 18.9
Long-term marketable debt securities | [2] | 8.3 |  | 9.4
Level 2 |  |  |  |
Financial Instruments [Line Items] |  |  |  |
Adjusted Cost Basis | [1] | 118.9 |  | 123.2
Unrealized Gain | [1] | 0.1 |  | 0.3
Unrealized Loss | [1] | 0.0 |  | 0.0
Fair Value | [1] | 119.0 |  | 123.5
Cash and cash equivalents | [1] | 0.5 |  | 3.5
Short-term marketable debt securities | [1] | 69.0 |  | 86.7
Long-term marketable debt securities | [1] | 49.5 |  | 33.3
Cash and Cash Equivalents |  |  |  |
Financial Instruments [Line Items] |  |  |  |
Adjusted Cost Basis |  | 1,695.4 |  | 970.5
Unrealized Gain |  | 0.0 |  | 0.0
Unrealized Loss |  | 0.0 |  | 0.0
Fair Value |  | 1,695.4 |  | 970.5
Cash and cash equivalents |  | 1,695.4 |  | 970.5
Short-term marketable debt securities |  | 0.0 |  | 0.0
Long-term marketable debt securities |  | 0.0 |  | 0.0
Money Market Fund | Level 1 |  |  |  |
Financial Instruments [Line Items] |  |  |  |
Adjusted Cost Basis | [2] | 7.0 |  | 0.6
Unrealized Gain | [2] | 0.0 |  | 0.0
Unrealized Loss | [2] | 0.0 |  | 0.0
Fair Value | [2] | 7.0 |  | 0.6
Cash and cash equivalents | [2] | 7.0 |  | 0.6
Short-term marketable debt securities | [2] | 0.0 |  | 0.0
Long-term marketable debt securities | [2] | 0.0 |  | 0.0
U.S. Treasury Securities | Level 1 |  |  |  |
Financial Instruments [Line Items] |  |  |  |
Adjusted Cost Basis | [2] | 27.6 |  | 28.1
Unrealized Gain | [2] | 0.0 |  | 0.2
Unrealized Loss | [2] | 0.0 |  | 0.0
Fair Value | [2] | 27.6 |  | 28.3
Cash and cash equivalents | [2] | 0.0 |  | 0.0
Short-term marketable debt securities | [2] | 19.3 |  | 18.9
Long-term marketable debt securities | [2] | 8.3 |  | 9.4
Certificates of Deposit | Level 2 |  |  |  |
Financial Instruments [Line Items] |  |  |  |
Adjusted Cost Basis | [1] | 3.9 |  | 5.9
Unrealized Gain | [1] | 0.0 |  | 0.0
Unrealized Loss | [1] | 0.0 |  | 0.0
Fair Value | [1] | 3.9 |  | 5.9
Cash and cash equivalents | [1] | 0.0 |  | 1.1
Short-term marketable debt securities | [1] | 3.9 |  | 4.8
Long-term marketable debt securities | [1] | 0.0 |  | 0.0
Commercial Paper | Level 2 |  |  |  |
Financial Instruments [Line Items] |  |  |  |
Adjusted Cost Basis | [1] |  |  | 3.2
Unrealized Gain | [1] |  |  | 0.0
Unrealized Loss | [1] |  |  | 0.0
Fair Value | [1] |  |  | 3.2
Cash and cash equivalents | [1] |  |  | 1.0
Short-term marketable debt securities | [1] |  |  | 2.2
Long-term marketable debt securities | [1] |  |  | 0.0
U.S. Government Agency Securities | Level 2 |  |  |  |
Financial Instruments [Line Items] |  |  |  |
Adjusted Cost Basis | [1] | 5.3 |  | 6.6
Unrealized Gain | [1] | 0.0 |  | 0.0
Unrealized Loss | [1] | 0.0 |  | 0.0
Fair Value | [1] | 5.3 |  | 6.6
Cash and cash equivalents | [1] | 0.0 |  | 0.0
Short-term marketable debt securities | [1] | 4.0 |  | 2.6
Long-term marketable debt securities | [1] | 1.3 |  | 4.0
Corporate Debt Securities | Level 2 |  |  |  |
Financial Instruments [Line Items] |  |  |  |
Adjusted Cost Basis | [1] | 109.7 |  | 107.5
Unrealized Gain | [1] | 0.1 |  | 0.3
Unrealized Loss | [1] | 0.0 |  | 0.0
Fair Value | [1] | 109.8 |  | 107.8
Cash and cash equivalents | [1] | 0.5 |  | 1.4
Short-term marketable debt securities | [1] | 61.1 |  | 77.1
Long-term marketable debt securities | [1] | $ 48.2 |  | $ 29.3
[1] | Valuations based on observable inputs other than quoted prices included in Level 1, such as quoted prices for similar assets and liabilities in active markets, quoted prices for identical or similar assets and liabilities in markets that are not active, or other inputs that are observable or can be corroborated by observable market data.
[2] | Valuations based on quoted prices for identical assets or liabilities in active markets.

X
- Definition Financial Instruments. + References No definition available. + Details
Name: | pkg_FinancialInstrumentsLineItems
Namespace Prefix: | pkg_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Unrealized gain on securities 1. + References No definition available. + Details
Name: | pkg_UnrealizedGainOnSecurities1
Namespace Prefix: | pkg_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Unrealized loss on securities 1. + References No definition available. + Details
Name: | pkg_UnrealizedLossOnSecurities1
Namespace Prefix: | pkg_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), classified as current. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=124258926&loc=SL82898722-210454 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=124260329&loc=d3e26626-111562 + Details
Name: | us-gaap_AvailableForSaleSecuritiesDebtSecuritiesCurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), classified as noncurrent. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=124258926&loc=SL82898722-210454 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=124260329&loc=d3e26626-111562 + Details
Name: | us-gaap_AvailableForSaleSecuritiesDebtSecuritiesNoncurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3044-108585 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section 45 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=124098289&loc=d3e6676-107765 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.1) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_CashAndCashEquivalentsAtCarryingValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Cost of the investment. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 946 -SubTopic 210 -Section 50 -Paragraph 6 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=99383244&loc=d3e12121-115841 + Details
Name: | us-gaap_InvestmentOwnedAtCost
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Value of the investment at close of period. For schedules of investments that are categorized, the value would be aggregated by category. For investment in and advances to affiliates, if operations of any controlled companies are different in character from those of the company, group such affiliates within divisions and by type of activities. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 946 -SubTopic 210 -Section 50 -Paragraph 6 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=99383244&loc=d3e12121-115841 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 946 -SubTopic 320 -Section S99 -Paragraph 5D -Subparagraph (SX 210.12-13D(Column C)) -URI http://asc.fasb.org/extlink&oid=122147990&loc=SL120429264-123010 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 946 -SubTopic 320 -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-12B(Column C)) -URI http://asc.fasb.org/extlink&oid=122147990&loc=d3e611197-123010 + Details
Name: | us-gaap_InvestmentOwnedAtFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_CashAndCashEquivalentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_MoneyMarketFundsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_USTreasurySecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_CertificatesOfDepositMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_CommercialPaperMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_USGovernmentAgenciesDebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_CorporateDebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |