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Amount, after investment expense, of income earned from investments in securities and real estate. Includes, but is not limited to, real estate investment, policy loans, dividends, and interest. Excludes realized gain (loss) on investments.

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Fair Value Measurements - Narratives (Details)	1 Months Ended	12 Months Ended
Fair Value Measurements - Narratives (Details)	Oct. 31, 2025 property	Dec. 31, 2025 USD ($) property $ / ft² shares	Dec. 31, 2024 USD ($) property	Dec. 31, 2023 USD ($) property $ / ft²
Fair Value Measurement Inputs and Valuation Techniques
Impairment charges — real estate		$ 70,367,000	$ 43,595,000	$ 86,411,000
Discontinued Operations, Disposed of by Sale
Fair Value Measurement Inputs and Valuation Techniques
Number of properties sold \| property		128	176	31
Discontinued Operations, Disposed of by Sale \| Office Sales Program
Fair Value Measurement Inputs and Valuation Techniques
Number of properties sold \| property	7	3
Disposal Group, Disposed of by Means Other than Sale, Not Discontinued Operations, Spinoff \| Office
Fair Value Measurement Inputs and Valuation Techniques
Impairment Charges			$ 20,600,000
Number of properties (property) \| property			2
Disposal Group, Disposed of by Means Other than Sale, Not Discontinued Operations, Spinoff \| NLOP \| Office
Fair Value Measurement Inputs and Valuation Techniques
Number of properties (property) \| property				59
Level 3 \| Fair Value, Measurements, Nonrecurring
Fair Value Measurement Inputs and Valuation Techniques
Impairment charges — real estate		$ 70,367,000	$ 43,595,000	$ 86,411,000
Impairment Charges		$ 70,367,000	43,595,000	86,411,000
Level 3 \| Fair Value, Measurements, Nonrecurring \| Minimum
Fair Value Measurement Inputs and Valuation Techniques
Market rent (usd per sqft) \| $ / ft²		35
Other real estate owned, estimated cash flow		$ 500,000
Level 3 \| Fair Value, Measurements, Nonrecurring \| Maximum
Fair Value Measurement Inputs and Valuation Techniques
Market rent (usd per sqft) \| $ / ft²		36
Other real estate owned, estimated cash flow		$ 1,000,000
Level 3 \| Fifteen Impaired Properties \| Fair Value, Measurements, Nonrecurring
Fair Value Measurement Inputs and Valuation Techniques
Impairment charges — real estate		$ 70,400,000
Impaired properties \| property		15
Level 3 \| Four impaired properties \| Fair Value, Measurements, Nonrecurring
Fair Value Measurement Inputs and Valuation Techniques
Impairment charges — real estate			$ 23,000,000.0
Impaired properties \| property			4
Number of properties sold \| property		2	2
Level 3 \| Spinoff properties \| Fair Value, Measurements, Nonrecurring
Fair Value Measurement Inputs and Valuation Techniques
Impairment charges — real estate				$ 47,300,000
Level 3 \| Spinoff properties \| Fair Value, Measurements, Nonrecurring \| Minimum
Fair Value Measurement Inputs and Valuation Techniques
Market rent (usd per sqft) \| $ / ft²				6
Level 3 \| Spinoff properties \| Fair Value, Measurements, Nonrecurring \| Minimum \| Measurement Input, Cashflow Discount Rate
Fair Value Measurement Inputs and Valuation Techniques
Real estate measurement input (percent)				0.065
Level 3 \| Spinoff properties \| Fair Value, Measurements, Nonrecurring \| Minimum \| Measurement Input, Terminal Capitalization Rate
Fair Value Measurement Inputs and Valuation Techniques
Real estate measurement input (percent)				0.055
Level 3 \| Spinoff properties \| Fair Value, Measurements, Nonrecurring \| Maximum
Fair Value Measurement Inputs and Valuation Techniques
Market rent (usd per sqft) \| $ / ft²				65
Level 3 \| Spinoff properties \| Fair Value, Measurements, Nonrecurring \| Maximum \| Measurement Input, Cashflow Discount Rate
Fair Value Measurement Inputs and Valuation Techniques
Real estate measurement input (percent)				0.120
Level 3 \| Spinoff properties \| Fair Value, Measurements, Nonrecurring \| Maximum \| Measurement Input, Terminal Capitalization Rate
Fair Value Measurement Inputs and Valuation Techniques
Real estate measurement input (percent)				0.120
Level 3 \| Eleven properties \| Fair Value, Measurements, Nonrecurring
Fair Value Measurement Inputs and Valuation Techniques
Impairment charges — real estate				$ 39,100,000
Number of properties (property) \| property				3
Investment in Lineage Logisitics \| Level 3
Fair Value Measurement Inputs and Valuation Techniques
Unrealized gain on investment		$ (103,400,000)	$ (134,000,000.0)	$ 0
Net investment income		11,300,000	7,900,000	$ 0
Investments, fair value disclosure		$ 167,500,000	$ 270,900,000
Investment in Lineage Logisitics \| Affiliated Entity \| Common stock
Fair Value Measurement Inputs and Valuation Techniques
Shares owned (in shares) \| shares		5,546,547