Investments - Commercial Mortgage Loan Participations Recorded Investment (Details) - Commercial mortgage loan participations - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying value, net of valuation allowance	$ 181,305	$ 141,843
Carrying value, net of valuation allowance, percent	100.00%	100.00%
Less than 70%
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying value, net of valuation allowance	$ 142,983	$ 94,322
Carrying value, net of valuation allowance, percent	79.00%	67.00%
70% to 80%
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying value, net of valuation allowance	$ 23,130	$ 26,035
Carrying value, net of valuation allowance, percent	13.00%	18.00%
81% to 90%
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying value, net of valuation allowance	$ 8,226	$ 8,166
Carrying value, net of valuation allowance, percent	4.00%	6.00%
Greater than 90%
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying value, net of valuation allowance	$ 6,966	$ 13,320
Carrying value, net of valuation allowance, percent	4.00%	9.00%
Less Than 1.00x
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying value, net of valuation allowance	$ 39,176	$ 36,825
Less Than 1.00x | Less than 70%
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying value, net of valuation allowance	23,984	13,650
Less Than 1.00x | 70% to 80%
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying value, net of valuation allowance	0	6,255
Less Than 1.00x | 81% to 90%
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying value, net of valuation allowance	8,226	8,166
Less Than 1.00x | Greater than 90%
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying value, net of valuation allowance	6,966	8,754
1.00x-1.20x
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying value, net of valuation allowance	129,003	105,018
1.00x-1.20x | Less than 70%
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying value, net of valuation allowance	107,099	80,672
1.00x-1.20x | 70% to 80%
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying value, net of valuation allowance	21,904	19,780
1.00x-1.20x | 81% to 90%
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying value, net of valuation allowance	0	0
1.00x-1.20x | Greater than 90%
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying value, net of valuation allowance	0	4,566
Greater Than 1.20x
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying value, net of valuation allowance	13,126	0
Greater Than 1.20x | Less than 70%
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying value, net of valuation allowance	11,900	0
Greater Than 1.20x | 70% to 80%
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying value, net of valuation allowance	1,226	0
Greater Than 1.20x | 81% to 90%
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying value, net of valuation allowance	0	0
Greater Than 1.20x | Greater than 90%
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying value, net of valuation allowance	$ 0	$ 0