Investments - Sale-Leaseback Transactions Accounted for as Financing Arrangements - Additional Information (Details) - USD ($) $ in Millions	Jun. 30, 2024	Dec. 31, 2023
Investments [Abstract]
Sale-leaseback transactions accounted for as financing arrangements	$ 999.3	$ 839.9

Represents element pertaining to sale-leaseback transactions accounted for as financing arrangements.

No definition available.

Name:	ck0001538990_SaleLeasebackTransactionsAccountedForAsFinancingArrangements
Namespace Prefix:	ck0001538990_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant