Fair Value of Financial Instruments - Carrying Value of Commercial Mortgage Loans and Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total amortized cost	$ 37,947	$ 47,201
Valuation allowance	(49)	(71)
Mortgage loans, net	37,898	47,130
Total mortgage loans | Mortgage Loans by Region
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage loans, net	$ 37,947	$ 47,201
Percent of Total	100.00%	100.00%
Total mortgage loans | Mortgage Loans by Region | East North Central
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage loans, net	$ 3,245	$ 3,245
Percent of Total	8.60%	6.90%
Total mortgage loans | Mortgage Loans by Region | Southern Atlantic
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage loans, net	$ 9,397	$ 9,578
Percent of Total	24.70%	20.30%
Total mortgage loans | Mortgage Loans by Region | East South Central
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage loans, net	$ 7,783	$ 8,028
Percent of Total	20.50%	17.00%
Total mortgage loans | Mortgage Loans by Region | New England
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage loans, net	$ 6,588	$ 6,588
Percent of Total	17.40%	14.00%
Total mortgage loans | Mortgage Loans by Region | Middle Atlantic
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage loans, net	$ 6,139	$ 14,789
Percent of Total	16.20%	31.30%
Total mortgage loans | Mortgage Loans by Region | Mountain
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage loans, net	$ 1,992	$ 2,227
Percent of Total	5.20%	4.70%
Total mortgage loans | Mortgage Loans by Region | West North Central
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage loans, net	$ 2,803	$ 2,746
Percent of Total	7.40%	5.80%
Total mortgage loans | Mortgage Loans by Property Type
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage loans, net	$ 37,947	$ 47,201
Percent of Total	100.00%	100.00%
Total mortgage loans | Mortgage Loans by Property Type | Multifamily
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage loans, net	$ 8,493	$ 16,986
Percent of Total	22.40%	36.00%
Total mortgage loans | Mortgage Loans by Property Type | Office
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage loans, net	$ 11,267	$ 11,571
Percent of Total	29.70%	24.50%
Total mortgage loans | Mortgage Loans by Property Type | Industrials
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage loans, net	$ 10,056	$ 10,124
Percent of Total	26.50%	21.50%
Total mortgage loans | Mortgage Loans by Property Type | Retail
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage loans, net	$ 1,992	$ 2,227
Percent of Total	5.20%	4.70%
Total mortgage loans | Mortgage Loans by Property Type | Mixed use/Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage loans, net	$ 6,139	$ 6,293
Percent of Total	16.20%	13.30%
Less than 65%
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total amortized cost	$ 29,231	$ 29,924
65%-75%
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total amortized cost	$ 8,716	$ 17,277