Organization and Summary of Significant Accounting Policies - Investments (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Equity Method Investees
Equity method investments	$ 1,774.9	$ 1,636.9
Penske Truck Leasing Co LP
Equity Method Investees
Equity method investments	$ 1,725.1	$ 1,590.9

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.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 323
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