Investments (Tables)

6 Months Ended

12 Months Ended

Jun. 30, 2024

Dec. 31, 2023

Investments

Available-for-Sale Securities (Table)

			Gross		Gross		Allowance
	Amortized		unrealized		unrealized		for credit
	cost (1)		gains		losses		loss		Fair value
	(in millions)
June 30, 2024
Fixed maturities, available-for-sale:
U.S. government and agencies	$	1,975.1	$	6.4	$	274.6	$	—	$	1,706.9
Non-U.S. governments		550.7		13.8		74.8		—		489.7
States and political subdivisions		7,280.1		17.2		1,058.5		—		6,238.8
Corporate		35,732.7		286.1		3,723.8		0.3		32,294.7
Residential mortgage-backed pass-through securities		3,203.0		8.5		200.9		—		3,010.6
Commercial mortgage-backed securities		5,369.1		1.4		515.7		—		4,854.8
Collateralized debt obligations (2)		5,815.1		60.8		8.2		—		5,867.7
Other debt obligations		8,903.9		35.0		620.1		0.1		8,318.7
Total fixed maturities, available-for-sale	$	68,829.7	$	429.2	$	6,476.6	$	0.4	$	62,781.9
December 31, 2023
Fixed maturities, available-for-sale:
U.S. government and agencies	$	1,719.1	$	19.3	$	233.5	$	—	$	1,504.9
Non-U.S. governments		522.2		16.9		59.2		—		479.9
States and political subdivisions		7,493.9		45.4		926.0		—		6,613.3
Corporate		35,707.6		433.7		3,059.9		1.9		33,079.5
Residential mortgage-backed pass-through securities		2,959.8		25.7		160.6		—		2,824.9
Commercial mortgage-backed securities		5,391.6		1.6		649.8		—		4,743.4
Collateralized debt obligations (2)		5,379.6		45.0		26.8		—		5,397.8
Other debt obligations		8,447.2		42.2		602.8		0.1		7,886.5
Total fixed maturities, available-for-sale	$	67,621.0	$	629.8	$	5,718.6	$	2.0	$	62,530.2

(1) Amortized cost excludes accrued interest receivable of $636.4 million and $616.0 million as of June 30, 2024 and December 31, 2023, respectively.

(2) Primarily consists of collateralized loan obligations backed by secured corporate loans.

			Gross		Gross		Allowance
	Amortized		unrealized		unrealized		for credit
	cost (1)		gains		losses		loss		Fair value
	(in millions)
December 31, 2023
Fixed maturities, available-for-sale:
U.S. government and agencies	$	1,719.1	$	19.3	$	233.5	$	—	$	1,504.9
Non-U.S. governments		522.2		16.9		59.2		—		479.9
States and political subdivisions		7,493.9		45.4		926.0		—		6,613.3
Corporate		35,707.6		433.7		3,059.9		1.9		33,079.5
Residential mortgage-backed pass-through securities		2,959.8		25.7		160.6		—		2,824.9
Commercial mortgage-backed securities		5,391.6		1.6		649.8		—		4,743.4
Collateralized debt obligations (2)		5,379.6		45.0		26.8		—		5,397.8
Other debt obligations		8,447.2		42.2		602.8		0.1		7,886.5
Total fixed maturities, available-for-sale	$	67,621.0	$	629.8	$	5,718.6	$	2.0	$	62,530.2
December 31, 2022
Fixed maturities, available-for-sale:
U.S. government and agencies	$	1,964.6	$	0.1	$	248.8	$	—	$	1,715.9
Non-U.S. governments		565.3		18.9		63.8		—		520.4
States and political subdivisions		7,280.1		14.8		1,126.6		—		6,168.3
Corporate		37,495.4		219.5		4,530.1		—		33,184.8
Residential mortgage-backed pass-through securities		2,362.1		6.0		197.2		—		2,170.9
Commercial mortgage-backed securities		5,529.7		0.9		703.1		—		4,827.5
Collateralized debt obligations (2)		4,698.9		4.5		143.2		—		4,560.2
Other debt obligations		7,207.8		6.0		730.4		0.1		6,483.3
Total fixed maturities, available-for-sale	$	67,103.9	$	270.7	$	7,743.2	$	0.1	$	59,631.3

(1) Amortized cost excludes accrued interest receivable of $616.0 million and $575.8 million as of December 31, 2023 and 2022, respectively.

(2) Primarily consists of collateralized loan obligations backed by secured corporate loans.

Fixed Maturities Available-for-Sale by Contractual Maturity (Table)

	Amortized cost		Fair value
	(in millions)
Due in one year or less	$	1,363.2	$	1,348.2
Due after one year through five years		8,011.1		7,782.9
Due after five years through ten years		9,287.7		8,716.9
Due after ten years		26,876.6		22,882.1
Subtotal		45,538.6		40,730.1
Mortgage-backed and other asset-backed securities		23,291.1		22,051.8
Total	$	68,829.7	$	62,781.9

	Amortized cost		Fair value
	(in millions)
Due in one year or less	$	1,298.4	$	1,282.2
Due after one year through five years		8,486.2		8,285.1
Due after five years through ten years		9,209.3		8,675.0
Due after ten years		26,448.9		23,435.3
Subtotal		45,442.8		41,677.6
Mortgage-backed and other asset-backed securities		22,178.2		20,852.6
Total	$	67,621.0	$	62,530.2

Net Investment Income (Table)

	For the year ended December 31,
	2023		2022		2021
	(in millions)
Fixed maturities, available-for-sale	$	2,230.0	$	1,734.4	$	2,483.8
Fixed maturities, trading		32.4		19.6		8.7
Equity securities		3.5		(35.4)		1.7
Mortgage loans		661.5		619.9		692.4
Real estate		177.2		276.2		194.4
Policy loans		39.1		34.4		36.2
Cash and cash equivalents		148.2		37.6		1.7
Derivatives		38.6		171.3		28.2
Other		231.6		194.8		362.0
Total		3,562.1		3,052.8		3,809.1
Investment expenses		(276.6)		(200.4)		(175.4)
Net investment income	$	3,285.5	$	2,852.4	$	3,633.7

Net Realized Capital Gains and Losses (Table)

	For the six months ended
	June 30,
	2024		2023
	(in millions)
Fixed maturities, available-for-sale:
Gross gains	$	2.7	$	37.5
Gross losses		(34.7)		(70.1)
Net credit losses (1)		(3.8)		(24.4)
Hedging, net (2)		(5.7)		(0.6)
Fixed maturities, trading (3)		1.2		(0.7)
Equity securities (4)		3.1		(0.9)
Mortgage loans		(47.5)		(74.3)
Derivatives (2)		22.6		(56.5)
Other		(9.0)		1.2
Net realized capital losses	$	(71.1)	$	(188.8)

(1) Net credit losses include adjustments to the credit loss valuation allowance, write-offs and recoveries on available-for-sale securities.

(2) The change in fair value of fixed maturities, available-for-sale and the change in fair value of derivative hedging instruments in fair value hedging relationships are reported in net investment income with the earnings effect of fixed maturities, available-for-sale. Gains (losses) for fixed maturities, available-for-sale related to terminated cash flow hedges continue to be reflected in net realized capital gains (losses).

(3) Unrealized gains (losses) on fixed maturities, trading still held at the reporting date were $0.7 million and $(1.8) million for the six months ended June 30, 2024 and 2023, respectively. This excludes $0.8 million and $1.1 million in unrealized gains (losses) for the six months ended June 30, 2024 and 2023, respectively, that were reported in market risk benefit remeasurement (gain) loss. In addition, this excludes $(2.3) million and $(1.9) million for the six months ended June 30, 2024 and 2023, respectively, that were reported in net realized capital gains (losses) on funds withheld assets.

(4) Unrealized gains (losses) on equity securities still held at the reporting date were $3.1 million and $(0.9) million for the six months ended June 30, 2024 and 2023, respectively. This excludes $0.0 million and $1.7 million for the six months ended June 30, 2024 and 2023, respectively, that were reported in net realized capital gains (losses) on funds withheld assets.

	For the year ended December 31,
	2023		2022		2021
	(in millions)
Fixed maturities, available-for-sale:
Gross gains	$	46.8	$	38.9	$	50.4
Gross losses		(134.8)		(120.7)		(26.9)
Net credit losses (1)		(31.3)		(11.5)		(34.5)
Hedging, net		2.2		(0.7)		(9.5)
Fixed maturities, trading (2)		0.7		(8.6)		(6.6)
Equity securities (3)		0.7		(7.4)		(0.5)
Mortgage loans (4)		(133.8)		(74.1)		5.3
Derivatives		(5.3)		154.7		126.4
Other		100.1		112.7		8.0
Net realized capital gains (losses)	$	(154.7)	$	83.3	$	112.1

(1) Net credit losses include adjustments to the credit loss valuation allowance, write-offs and recoveries on available-for-sale securities.

(2) Unrealized losses on fixed maturities, trading still held at the reporting date were $(0.2) million, $(7.8) million and $(6.4) million for the years ended December 31, 2023, 2022 and 2021, respectively. This excludes $(2.9) million, $16.6 million and $0.0 million in unrealized gains (losses) for the years ended December 31, 2023, 2022 and 2021, respectively, that were reported in market risk benefit remeasurement (gain) loss and $6.8 million, $(1.4) million and $0.0 million of unrealized gains (losses) for the years ended December 31, 2023, 2022 and 2021, respectively, that were reported in net realized capital gains (losses) on funds withheld assets.

(3) Unrealized gains (losses) on equity securities still held at the reporting date were $0.7 million , $(7.1) million and $(0.1) million for the years ended December 31, 2023, 2022 and 2021, respectively. This excludes $1.7 million , $(1.7) million and $0.0 million unrealized gains (losses) for the years ended December 31, 2023, 2022 and 2021, respectively, that were reported in net realized capital gains (losses) on funds withheld assets.

(4) Net realized capital gains (losses) on mortgage loans include losses related to the deconsolidation of residential mortgage loan trusts in both 2023 and 2022.

Allowance for credit loss (Tables)

	For the six months ended June 30, 2024
									Residential
									mortgage-
									backed		Commercial		Collateralized
	U.S.				States and				pass-		mortgage-		debt		Other
	government		Non-U.S.		political				through		backed		obligations		debt
	and agencies		governments		subdivisions		Corporate		securities		securities		(1)		obligations		Total
	(in millions)
Beginning balance	$	—	$	—	$	—	$	1.9	$	—	$	—	$	—	$	0.1	$	2.0
Write-offs charged against allowance		—		—		—		(1.6)		—		—		—		—		(1.6)
Ending balance	$	—	$	—	$	—	$	0.3	$	—	$	—	$	—	$	0.1	$	0.4

	For the six months ended June 30, 2023
									Residential
									mortgage-
									backed		Commercial		Collateralized
	U.S.				States and				pass-		mortgage-		debt		Other
	government		Non-U.S.		political				through		backed		obligations		debt
	and agencies		governments		subdivisions		Corporate		securities		securities		(1)		obligations		Total
	(in millions)
Beginning balance	$	—	$	—	$	—	$	—	$	—	$	—	$	—	$	0.1	$	0.1
Additions for credit losses not previously recorded		—		—		—		3.8		—		—		—		—		3.8
Ending balance	$	—	$	—	$	—	$	3.8	$	—	$	—	$	—	$	0.1	$	3.9

(1) Primarily consists of collateralized loan obligations backed by secured corporate loans.

	For the year ended December 31, 2023
									Residential
									mortgage-
									backed		Commercial		Collateralized
	U.S.				States and				pass-		mortgage-		debt		Other
	government		Non-U.S.		political				through		backed		obligations		debt
	and agencies		governments		subdivisions		Corporate		securities		securities		(1)		obligations		Total
	(in millions)
Beginning balance	$	—	$	—	$	—	$	—	$	—	$	—	$	—	$	0.1	$	0.1
Additions for credit losses not previously recorded		—		—		—		5.7		—		—		—		—		5.7
Write-offs charged against allowance		—		—		—		(3.8)		—		—		—		—		(3.8)
Ending balance	$	—	$	—	$	—	$	1.9	$	—	$	—	$	—	$	0.1	$	2.0
Accrued interest written off to net investment income	$	—	$	—	$	—	$	0.1	$	—	$	—	$	—	$	—	$	0.1

	For the year ended December 31, 2022
									Residential
									mortgage-
									backed		Commercial		Collateralized
	U.S.				States and				pass-		mortgage-		debt		Other
	government		Non-U.S.		political				through		backed		obligations		debt
	and agencies		governments		subdivisions		Corporate		securities		securities		(1)		obligations		Total
	(in millions)
Beginning balance	$	—	$	—	$	—	$	4.5	$	—	$	0.3	$	—	$	0.1	$	4.9
Reductions for securities sold during the period		—		—		—		(8.7)		—		—		—		—		(8.7)
Additional increases (decreases) for credit losses on securities with an allowance recorded in the previous period		—		—		—		4.2		—		—		—		—		4.2
Write-offs charged against allowance		—		—		—		—		—		(0.3)		—		—		(0.3)
Ending balance	$	—	$	—	$	—	$	—	$	—	$	—	$	—	$	0.1	$	0.1

	For the year ended December 31, 2021
									Residential
									mortgage-
									backed		Commercial		Collateralized
	U.S.				States and				pass-		mortgage-		debt		Other
	government		Non-U.S.		political				through		backed		obligations		debt
	and agencies		governments		subdivisions		Corporate		securities		securities		(1)		obligations		Total
	(in millions)
Beginning balance	$	—	$	—	$	—	$	—	$	—	$	4.3	$	2.2	$	—	$	6.5
Additions for credit losses not previously recorded		—		—		—		16.9		—		0.4		—		0.1		17.4
Reductions for securities sold during the period		—		—		—		(12.4)		—		—		—		—		(12.4)
Additional increases (decreases) for credit losses on securities with an allowance recorded in the previous period		—		—		—		—		—		2.4		0.4		—		2.8
Write-offs charged against allowance		—		—		—		—		—		(6.8)		(2.6)		—		(9.4)
Ending balance	$	—	$	—	$	—	$	4.5	$	—	$	0.3	$	—	$	0.1	$	4.9
Accrued interest written off to net investment income	$	—	$	—	$	—	$	0.2	$	—	$	—	$	—	$	—	$	0.2

(1) Primarily consists of collateralized loan obligations backed by secured corporate loans.

Available-for-Sale Securities in Unrealized Loss Positions Without an Allowance for Credit Loss (Table)

	June 30, 2024
	Less than				Greater than or
	twelve months				equal to twelve months				Total
			Gross				Gross				Gross
	Fair		unrealized		Fair		unrealized		Fair		unrealized
	value		losses		value		losses		value		losses
	(in millions)
Fixed maturities, available-for-sale (1):
U.S. government and agencies	$	198.4	$	5.5	$	1,052.0	$	269.1	$	1,250.4	$	274.6
Non-U.S. governments		41.2		3.1		305.0		71.7		346.2		74.8
States and political subdivisions		701.5		30.8		4,840.2		1,027.7		5,541.7		1,058.5
Corporate		3,924.6		167.3		20,686.1		3,556.5		24,610.7		3,723.8
Residential mortgage-backed pass- through securities		994.9		10.4		1,586.1		190.5		2,581.0		200.9
Commercial mortgage-backed securities		476.5		3.0		4,135.8		512.7		4,612.3		515.7
Collateralized debt obligations (2)		591.6		0.9		403.1		7.3		994.7		8.2
Other debt obligations		1,231.5		13.0		4,536.0		607.1		5,767.5		620.1
Total fixed maturities, available-for-sale	$	8,160.2	$	234.0	$	37,544.3	$	6,242.6	$	45,704.5	$	6,476.6

(1) Fair value and gross unrealized losses are excluded for available-for-sale securities for which an allowance for credit loss has been recorded.

(2) Primarily consists of collateralized loan obligations backed by secured corporate loans.

	December 31, 2023
	Less than				Greater than or
	twelve months				equal to twelve months				Total
			Gross				Gross				Gross
	Fair		unrealized		Fair		unrealized		Fair		unrealized
	value		losses		value		losses		value		losses
	(in millions)
Fixed maturities, available-for-sale (1):
U.S. government and agencies	$	315.3	$	3.1	$	974.2	$	230.5	$	1,289.5	$	233.6
Non-U.S. governments		41.9		1.7		307.9		57.5		349.8		59.2
States and political subdivisions		596.6		19.0		5,011.7		906.9		5,608.3		925.9
Corporate		2,540.5		89.7		22,305.9		2,968.9		24,846.4		3,058.6
Residential mortgage-backed pass-through securities		472.9		2.9		1,275.6		157.7		1,748.5		160.6
Commercial mortgage-backed securities		280.3		4.1		4,160.3		645.6		4,440.6		649.7
Collateralized debt obligations (2)		404.8		1.5		2,296.3		25.3		2,701.1		26.8
Other debt obligations		1,183.7		18.5		4,386.0		584.2		5,569.7		602.7
Total fixed maturities, available-for-sale	$	5,836.0	$	140.5	$	40,717.9	$	5,576.6	$	46,553.9	$	5,717.1

(1) Fair value and gross unrealized losses are excluded for available-for-sale securities for which an allowance for credit loss has been recorded.

(2) Primarily consists of collateralized loan obligations backed by secured corporate loans.

	December 31, 2023
	Less than				Greater than or
	twelve months				equal to twelve months				Total
			Gross				Gross				Gross
	Fair		unrealized		Fair		unrealized		Fair		unrealized
	value		losses		value		losses		value		losses
	(in millions)
Fixed maturities, available-for-sale (1):
U.S. government and agencies	$	315.3	$	3.1	$	974.2	$	230.5	$	1,289.5	$	233.6
Non-U.S. governments		41.9		1.7		307.9		57.5		349.8		59.2
States and political subdivisions		596.6		19.0		5,011.7		906.9		5,608.3		925.9
Corporate		2,540.5		89.7		22,305.9		2,968.9		24,846.4		3,058.6
Residential mortgage-backed pass- through securities		472.9		2.9		1,275.6		157.7		1,748.5		160.6
Commercial mortgage-backed securities		280.3		4.1		4,160.3		645.6		4,440.6		649.7
Collateralized debt obligations (2)		404.8		1.5		2,296.3		25.3		2,701.1		26.8
Other debt obligations		1,183.7		18.5		4,386.0		584.2		5,569.7		602.7
Total fixed maturities, available-for-sale	$	5,836.0	$	140.5	$	40,717.9	$	5,576.6	$	46,553.9	$	5,717.1

(1) Fair value and gross unrealized losses are excluded for available-for-sale securities for which an allowance for credit loss has been recorded.

(2) Primarily consists of collateralized loan obligations backed by secured corporate loans.

	December 31, 2022
	Less than				Greater than or
	twelve months				equal to twelve months				Total
			Gross				Gross				Gross
	Fair		unrealized		Fair		unrealized		Fair		unrealized
	value		losses		value		losses		value		losses
	(in millions)
Fixed maturities, available-for-sale (1):
U.S. government and agencies	$	1,505.5	$	207.0	$	180.4	$	41.8	$	1,685.9	$	248.8
Non-U.S. governments		373.0		56.7		19.9		7.1		392.9		63.8
States and political subdivisions		5,243.6		999.7		387.8		126.9		5,631.4		1,126.6
Corporate		26,668.2		3,875.1		2,625.4		654.9		29,293.6		4,530.0
Residential mortgage-backed pass-through securities		1,201.7		97.6		574.8		104.7		1,776.5		202.3
Commercial mortgage-backed securities		3,622.3		480.7		1,113.9		220.9		4,736.2		701.6
Collateralized debt obligations (2)		2,830.1		88.8		1,327.2		54.4		4,157.3		143.2
Other debt obligations		3,412.6		290.7		2,266.7		434.4		5,679.3		725.1
Total fixed maturities, available-for-sale	$	44,857.0	$	6,096.3	$	8,496.1	$	1,645.1	$	53,353.1	$	7,741.4

(1) Fair value and gross unrealized losses are excluded for available-for-sale securities for which an allowance for credit loss has been recorded.

(2) Primarily consists of collateralized loan obligations backed by secured corporate loans.

Net Unrealized Gains and Losses on Available-for-Sale Securities and Derivative Instruments (Table)

	June 30, 2024		December 31, 2023
	(in millions)
Net unrealized losses on fixed maturities, available-for-sale (1)	$	(6,150.9)	$	(5,128.4)
Net unrealized gains (losses) on derivative instruments		51.1		(1.6)
Adjustments for assumed changes in amortization patterns		(0.7)		(5.2)
Adjustments for assumed changes in policyholder liabilities		12.1		1.4
Net unrealized gains on other investments and noncontrolling interest adjustments		2.9		2.9
Provision for deferred income tax benefits		1,296.9		1,099.6
Net unrealized losses on available-for-sale securities and derivative instruments	$	(4,788.6)	$	(4,031.3)

(1) Excludes net unrealized gains (losses) on fixed maturities, available-for-sale included in fair value hedging relationships.

	December 31, 2023		December 31, 2022
	(in millions)
Net unrealized losses on fixed maturities, available-for-sale (1)	$	(5,128.4)	$	(7,552.6)
Net unrealized gains (losses) on derivative instruments		(1.6)		50.7
Adjustments for assumed changes in amortization patterns		(5.2)		(1.8)
Adjustments for assumed changes in policyholder liabilities		1.4		0.5
Net unrealized gains on other investments and noncontrolling interest adjustments		2.9		2.9
Provision for deferred income tax benefits		1,099.6		1,601.5
Net unrealized losses on available-for-sale securities and derivative instruments	$	(4,031.3)	$	(5,898.8)

(1) Excludes net unrealized gains (losses) on fixed maturities, available-for-sale included in fair value hedging relationships.

Financing Receivable Credit Quality Indicators (Table)

	June 30, 2024
	2024		2023		2022		2021		2020		Prior		Total
	(in millions)
Commercial mortgage loans:
A- and above	$	547.3	$	815.7	$	1,219.2	$	2,182.3	$	1,508.8	$	6,996.6	$	13,269.9
BBB+ thru BBB-		85.9		307.0		293.2		235.4		163.0		1,059.5		2,144.0
BB+ thru BB-		16.7		126.7		151.5		44.1		40.3		239.5		618.8
B+ and below		—		—		—		—		—		367.6		367.6
Total	$	649.9	$	1,249.4	$	1,663.9	$	2,461.8	$	1,712.1	$	8,663.2	$	16,400.3
Residential mortgage
loans:
Performing	$	88.4	$	400.9	$	980.3	$	1,227.9	$	138.9	$	311.0	$	3,147.4
Non-performing		—		1.2		4.6		3.9		1.2		3.9		14.8
Total	$	88.4	$	402.1	$	984.9	$	1,231.8	$	140.1	$	314.9	$	3,162.2
Other loans:
Performing	$	84.5	$	98.8	$	—	$	—	$	—	$	—	$	183.3
Non-performing		0.1		—		—		—		—		0.1		0.2
Total	$	84.6	$	98.8	$	—	$	—	$	—	$	0.1	$	183.5
Reinsurance recoverable and deposit receivable													$	23,375.0

	December 31, 2023
	2023		2022		2021		2020		2019		Prior		Total
		(in millions)
Commercial mortgage loans:
A- and above	$	667.4	$	1,214.8	$	2,271.5	$	1,535.8	$	1,921.0	$	5,447.2	$	13,057.7
BBB+ thru BBB-		282.6		356.8		343.0		203.3		309.9		886.9		2,382.5
BB+ thru BB-		110.6		142.1		—		—		35.3		234.6		522.6
B+ and below		—		—		—		—		83.5		53.9		137.4
Total	$	1,060.6	$	1,713.7	$	2,614.5	$	1,739.1	$	2,349.7	$	6,622.6	$	16,100.2
Residential mortgage loans:
Performing	$	456.3	$	1,023.4	$	1,272.5	$	150.4	$	86.8	$	253.6	$	3,243.0
Non-performing		—		2.1		4.0		—		1.8		2.3		10.2
Total	$	456.3	$	1,025.5	$	1,276.5	$	150.4	$	88.6	$	255.9	$	3,253.2
Other loans:
Performing	$	168.5	$	—	$	—	$	—	$	—	$	—	$	168.5
Non-performing		—		—		—		—		—		0.1		0.1
Total	$	168.5	$	—	$	—	$	—	$	—	$	0.1	$	168.6
Reinsurance recoverable and deposit receivable													$	24,427.9

	December 31, 2023
	2023		2022		2021		2020		2019		Prior		Total
	(in millions)
Commercial mortgage loans:
A- and above	$	667.4	$	1,214.8	$	2,271.5	$	1,535.8	$	1,921.0	$	5,447.2	$	13,057.7
BBB+ thru BBB-		282.6		356.8		343.0		203.3		309.9		886.9		2,382.5
BB+ thru BB-		110.6		142.1		—		—		35.3		234.6		522.6
B+ and below		—		—		—		—		83.5		53.9		137.4
Total	$	1,060.6	$	1,713.7	$	2,614.5	$	1,739.1	$	2,349.7	$	6,622.6	$	16,100.2
Residential mortgage
loans:
Performing	$	456.3	$	1,023.4	$	1,272.5	$	150.4	$	86.8	$	253.6	$	3,243.0
Non-performing		—		2.1		4.0		—		1.8		2.3		10.2
Total	$	456.3	$	1,025.5	$	1,276.5	$	150.4	$	88.6	$	255.9	$	3,253.2
Other loans:
Performing	$	168.5	$	—	$	—	$	—	$	—	$	—	$	168.5
Non-performing		—		—		—		—		—		0.1		0.1
Total	$	168.5	$	—	$	—	$	—	$	—	$	0.1	$	168.6
Reinsurance recoverable and deposit receivable													$	24,427.9

	December 31, 2022
	2022		2021		2020		2019		2018		Prior		Total
		(in millions)
Commercial mortgage loans:
A- and above	$	995.9	$	2,182.5	$	1,753.8	$	2,177.2	$	2,130.8	$	4,555.1	$	13,795.3
BBB+ thru BBB-		371.8		412.8		149.7		391.6		222.6		676.4		2,224.9
BB+ thru BB-		104.0		—		—		—		8.9		66.5		179.4
B+ and below		—		—		—		—		8.3		35.5		43.8
Total	$	1,471.7	$	2,595.3	$	1,903.5	$	2,568.8	$	2,370.6	$	5,333.5	$	16,243.4
Residential mortgage loans:
Performing	$	1,101.4	$	1,669.1	$	364.5	$	99.2	$	51.2	$	253.6	$	3,539.0
Non-performing		8.0		4.7		1.8		1.0		0.6		4.4		20.5
Total	$	1,109.4	$	1,673.8	$	366.3	$	100.2	$	51.8	$	258.0	$	3,559.5
Reinsurance recoverable and deposit receivable													$	21,445.0

Non-Accrual Financing Receivables (Table)

	June 30, 2024
					Amortized cost
	Beginning		Ending		of nonaccrual
	amortized cost		amortized cost		assets without
	on nonaccrual		on nonaccrual		a valuation
	status		status		allowance
	(in millions)
Commercial mortgage loans	$	53.9	$	137.0	$	—
Residential mortgage loans		8.2		12.4		—
Total	$	62.1	$	149.4	$	—

	December 31, 2023
					Amortized cost
	Beginning		Ending		of nonaccrual
	amortized cost		amortized cost		assets without
	on nonaccrual		on nonaccrual		a valuation
	status		status		allowance
	(in millions)
Commercial mortgage loans	$	43.8	$	53.9	$	—
Residential mortgage loans		16.0		8.2		0.5
Total	$	59.8	$	62.1	$	0.5

	December 31, 2023
					Amortized cost
	Beginning		Ending		of nonaccrual
	amortized cost		amortized cost		assets without
	on nonaccrual		on nonaccrual		a valuation
	status		status		allowance
	(in millions)
Commercial mortgage loans	$	43.8	$	53.9	$	—
Residential mortgage loans		16.0		8.2		0.5
Total	$	59.8	$	62.1	$	0.5

	December 31, 2022
					Amortized cost
	Beginning		Ending		of nonaccrual
	amortized cost		amortized cost		assets without
	on nonaccrual		on nonaccrual		a valuation
	status		status		allowance
	(in millions)
Commercial mortgage loans	$	8.7	$	43.8	$	—
Residential mortgage loans		3.4		16.0		0.6
Total	$	12.1	$	59.8	$	0.6

Schedule of Interest Income Recognized on Non-accrual Financing Receivables (Table)

	For the six months ended June 30,
	2024		2023
	(in millions)
Commercial mortgage loans	$	(0.2)	$	—
Residential mortgage loans		0.1		—
Total	$	(0.1)	$	—

	For the year ended December 31,
	2023		2022		2021
	(in millions)
Commercial mortgage loans	$	1.2	$	0.9	$	0.5
Total	$	1.2	$	0.9	$	0.5

Financing Receivables Aging (Table)

	June 30, 2024
					90 days or								90 days or
	30-59 days		60-89 days		more past		Total						more and
	past due		past due		due		past due		Current		Total (1)		accruing
	(in millions)
Commercial mortgage loans	$	—	$	59.5	$	91.4	$	150.9	$	16,249.4	$	16,400.3	$	—
Residential mortgage loans		8.1		0.5		10.8		19.4		3,142.8		3,162.2		2.4
Other loans		2.0		1.6		1.7		5.3		178.2		183.5		1.5
Total	$	10.1	$	61.6	$	103.9	$	175.6	$	19,570.4	$	19,746.0	$	3.9

	December 31, 2023
					90 days or								90 days or
	30-59 days		60-89 days		more past		Total						more and
	past due		past due		due		past due		Current		Total (1)		accruing
	(in millions)
Commercial mortgage loans	$	—	$	—	$	7.9	$	7.9	$	16,092.3	$	16,100.2	$	—
Residential mortgage loans		8.5		1.8		8.7		19.0		3,234.2		3,253.2		2.0
Other loans		1.0		0.5		0.7		2.2		166.4		168.6		0.6
Total	$	9.5	$	2.3	$	17.3	$	29.1	$	19,492.9	$	19,522.0	$	2.6

(1) As of both June 30, 2024 and December 31, 2023, no reinsurance recoverables or deposit receivables were considered past due.

	December 31, 2023
					90 days or								90 days or
	30-59 days		60-89 days		more past		Total						more and
	past due		past due		due		past due		Current		Total (1)		accruing
	(in millions)
Commercial mortgage loans	$	—	$	—	$	7.9	$	7.9	$	16,092.3	$	16,100.2	$	—
Residential mortgage loans		8.5		1.8		8.7		19.0		3,234.2		3,253.2		2.0
Other loans		1.0		0.5		0.7		2.2		166.4		168.6		0.6
Total	$	9.5	$	2.3	$	17.3	$	29.1	$	19,492.9	$	19,522.0	$	2.6

	December 31, 2022
					90 days or								90 days or
	30-59 days		60-89 days		more past		Total						more and
	past due		past due		due		past due		Current		Total (1)		accruing
	(in millions)
Commercial mortgage loans	$	—	$	—	$	8.3	$	8.3	$	16,235.1	$	16,243.4	$	—
Residential mortgage loans		35.9		2.4		12.4		50.7		3,508.8		3,559.5		4.4
Total	$	35.9	$	2.4	$	20.7	$	59.0	$	19,743.9	$	19,802.9	$	4.4

(1) As of both December 31, 2023 and 2022, no reinsurance recoverables or deposit receivables were considered past due.

Financing Receivables Valuation Allowance (Table)

	For the six months ended June 30, 2024
	Commercial		Residential		Reinsurance
	mortgage loans		mortgage loans		recoverables		Total
		(in millions)
Beginning balance	$	126.1	$	6.1	$	3.2	$	135.4
Provision		48.2		2.5		(0.1)		50.6
Charge-offs		(11.8)		(0.1)		—		(11.9)
Recoveries		—		0.4		—		0.4
Ending balance	$	162.5	$	8.9	$	3.1	$	174.5

	For the six months ended June 30, 2023
	Commercial		Residential		Reinsurance
	mortgage loans		mortgage loans		recoverables		Total
		(in millions)
Beginning balance	$	75.5	$	5.0	$	2.7	$	83.2
Provision		23.4		0.5		—		23.9
Charge-offs		—		(0.1)		—		(0.1)
Recoveries		—		0.7		—		0.7
Ending balance	$	98.9	$	6.1	$	2.7	$	107.7

	For the year ended December 31, 2023
	Commercial		Residential		Reinsurance
	mortgage loans		mortgage loans		recoverables		Total
		(in millions)
Beginning balance	$	75.5	$	5.0	$	2.7	$	83.2
Provision		50.6		—		0.5		51.1
Charge-offs		—		(0.4)		—		(0.4)
Recoveries		—		1.5		—		1.5
Ending balance	$	126.1	$	6.1	$	3.2	$	135.4

	For the year ended December 31, 2022
	Commercial		Residential		Reinsurance
	mortgage loans		mortgage loans		recoverables		Total
		(in millions)
Beginning balance	$	42.0	$	1.7	$	2.7	$	46.4
Provision		33.5		1.2		—		34.7
Charge-offs		—		(0.2)		—		(0.2)
Recoveries		—		2.3		—		2.3
Ending balance	$	75.5	$	5.0	$	2.7	$	83.2

	For the year ended December 31, 2021
	Commercial		Residential		Reinsurance
	mortgage loans		mortgage loans		recoverables		Total
		(in millions)
Beginning balance	$	40.5	$	5.7	$	2.7	$	48.9
Provision (1)		1.5		(7.2)		—		(5.7)
Charge-offs		—		(0.5)		—		(0.5)
Recoveries		—		3.7		—		3.7
Ending balance	$	42.0	$	1.7	$	2.7	$	46.4

(1) During the year ended December 31, 2021, certain valuation allowances for residential mortgage loans were released. This release was a result of further adjustments to our current and forecasted environmental factors management believed to be relevant as global economic activity improved from previously adverse impacts due to COVID-19.

For the years ended December 31, 2023, 2022 and 2021, no allowance was recorded for other loans.

Mortgage Loans Purchased and Sold (Table)

	For the six months ended June 30,
	2024		2023
	(in millions)
Commercial mortgage loans:
Purchased	$	50.1	$	106.8
Residential mortgage loans:
Purchased (1)		74.2		394.0
Sold		—		13.2

(1) Includes mortgage loans purchased by residential mortgage loan VIEs in 2023.

	For the year ended December 31,
	2023		2022		2021
	(in millions)
Commercial mortgage loans:
Purchased	$	108.1	$	261.3	$	—
Residential mortgage loans:
Purchased (1)		505.6		1,805.2		2,272.4
Sold		99.3		512.8		—

(1) Includes mortgage loans purchased by residential mortgage loan VIEs.

Commercial Mortgage Loans by Geographic Distribution and Property Type Distribution (Table)

	June 30, 2024				December 31, 2023
	Amortized		Percent		Amortized		Percent
	cost		of total		cost		of total
	($ in millions)
Geographic distribution
New England	$	353.3	2.2	%	$	367.6	2.3	%
Middle Atlantic		4,587.2	27.9			4,525.0	28.1
East North Central		591.9	3.6			584.5	3.6
West North Central		352.9	2.2			336.9	2.1
South Atlantic		2,880.9	17.6			2,768.8	17.2
East South Central		475.3	2.9			430.3	2.7
West South Central		1,277.4	7.8			1,272.0	7.9
Mountain		874.1	5.3			825.9	5.1
Pacific		5,007.3	30.5			4,989.2	31.0
Total	$	16,400.3	100.0	%	$	16,100.2	100.0	%
Property type distribution
Office	$	3,452.1	21.0	%	$	3,651.5	22.7	%
Retail		1,431.0	8.7			1,457.4	9.1
Industrial		3,891.5	23.7			3,526.7	21.9
Apartments		7,260.9	44.4			7,148.5	44.4
Hotel		66.8	0.4			68.6	0.4
Mixed use/other		298.0	1.8			247.5	1.5
Total	$	16,400.3	100.0	%	$	16,100.2	100.0	%

	December 31, 2023				December 31, 2022
	Amortized		Percent		Amortized		Percent
	cost		of total		cost		of total
	($ in millions)
Geographic distribution
New England	$	367.6	2.3	%	$	513.3	3.2	%
Middle Atlantic		4,525.0	28.1			4,518.8	27.8
East North Central		584.5	3.6			653.9	4.0
West North Central		336.9	2.1			371.9	2.3
South Atlantic		2,768.8	17.2			2,565.5	15.8
East South Central		430.3	2.7			340.6	2.1
West South Central		1,272.0	7.9			1,208.8	7.4
Mountain		825.9	5.1			940.9	5.8
Pacific		4,989.2	31.0			5,129.7	31.6
Total	$	16,100.2	100.0	%	$	16,243.4	100.0	%
Property type distribution
Office	$	3,651.5	22.7	%	$	4,331.8	26.7	%
Retail		1,457.4	9.1			1,502.5	9.2
Industrial		3,526.7	21.9			3,246.4	20.0
Apartments		7,148.5	44.4			6,848.3	42.2
Hotel		68.6	0.4			72.5	0.4
Mixed use/other		247.5	1.5			241.9	1.5
Total	$	16,100.2	100.0	%	$	16,243.4	100.0	%

Mortgage Loans Modified as a Troubled Debt Restructuring (Table)

	For the year ended December 31, 2022
	TDRs			TDRs in payment default
	Number of	Recorded		Number of	Recorded
	contracts	investment		contracts	investment
			(in millions)			(in millions)
Commercial mortgage loans	1	$	35.5	—	$	—
Total	1	$	35.5	—	$	—

Minority Interests in Unconsolidated Entities-Balance Sheet (Table)

	December 31,
	2023		2022
	(in millions)
Total assets	$	119,329.9	$	128,765.7
Total liabilities		16,131.8		12,335.4
Total equity	$	103,198.1	$	116,430.3
Net investment in unconsolidated entities	$	1,869.9	$	1,275.5

Minority Interests in Unconsolidated Entities-Income Statement (Table)

	For the year ended
	December 31,
	2023		2022		2021
	(in millions)
Total revenues	$	2,555.9	$	36,915.1	$	17,674.2
Net income		(3,110.6)		33,194.6		14,083.1
Our share of net income of unconsolidated entities		151.0		119.5		229.6

Financial Assets Subject to Netting Agreements (Table)

		Gross amounts not offset in the
		consolidated statements
		of financial position
	Gross amount
	of recognized		Financial		Collateral
	assets (1)		instruments (2)		received		Net amount
	(in millions)
June 30, 2024
Derivative assets	$	384.7	$	(180.6)	$	(184.4)	$	19.7
Reverse repurchase agreements		103.4		—		(103.4)		—
Total	$	488.1	$	(180.6)	$	(287.8)	$	19.7
December 31, 2023
Derivative assets	$	253.0	$	(166.0)	$	(81.0)	$	6.0
Reverse repurchase agreements		122.7		—		(122.7)		—
Total	$	375.7	$	(166.0)	$	(203.7)	$	6.0

(1) The gross amount of recognized derivative and reverse repurchase agreement assets are reported with other investments and cash and cash equivalents, respectively, on the consolidated statements of financial position. The gross amounts of derivative and reverse repurchase agreement assets are not netted against offsetting liabilities for presentation on the consolidated statements of financial position.

(2) Represents amount of offsetting derivative liabilities that are subject to an enforceable master netting agreement or similar agreement that are not netted against the gross derivative assets for presentation on the consolidated statements of financial position.

		Gross amounts not offset in the
		consolidated statements
		of financial position
	Gross amount
	of recognized		Financial		Collateral
	assets (1)		instruments (2)		received		Net amount
	(in millions)
December 31, 2023
Derivative assets	$	253.0	$	(166.0)	$	(81.0)	$	6.0
Reverse repurchase agreements		122.7		—		(122.7)		—
Total	$	375.7	$	(166.0)	$	(203.7)	$	6.0
December 31, 2022
Derivative assets	$	256.6	$	(133.5)	$	(120.8)	$	2.3
Reverse repurchase agreements		112.9		—		(112.9)		—
Total	$	369.5	$	(133.5)	$	(233.7)	$	2.3

(1) The gross amount of recognized derivative and reverse repurchase agreement assets are reported with other investments and cash and cash equivalents, respectively, on the consolidated statements of financial position. The gross amounts of derivative and reverse repurchase agreement assets are not netted against offsetting liabilities for presentation on the consolidated statements of financial position.

(2) Represents amount of offsetting derivative liabilities that are subject to an enforceable master netting agreement or similar agreement that are not netted against the gross derivative assets for presentation on the consolidated statements of financial position.

Financial Liabilities Subject to Netting Agreements (Table)

			Gross amounts not offset in the
			consolidated statements
			of financial position
	Gross amount
	of recognized		Financial		Collateral
	liabilities (1)		instruments (2)		pledged		Net amount
	(in millions)
June 30, 2024
Derivative liabilities	$	456.7	$	(180.6)	$	(253.5)	$	22.6
December 31, 2023
Derivative liabilities	$	473.4	$	(166.0)	$	(295.5)	$	11.9

(1) The gross amount of recognized derivative liabilities is reported with other liabilities on the consolidated statements of financial position. The above excludes derivative liabilities, which are primarily embedded derivatives that are not subject to master netting agreements or similar agreements. The gross amounts of derivative liabilities are not netted against offsetting assets for presentation on the consolidated statements of financial position.

(2) Represents amount of offsetting derivative assets that are subject to an enforceable master netting agreement or similar agreement that are not netted against the gross derivative liabilities for presentation on the consolidated statements of financial position.

			Gross amounts not offset in the
			consolidated statements
			of financial position
	Gross amount
	of recognized		Financial		Collateral
	liabilities (1)		instruments (2)		pledged		Net amount
	(in millions)
December 31, 2023
Derivative liabilities	$	473.4	$	(166.0)	$	(295.5)	$	11.9
December 31, 2022
Derivative liabilities	$	612.2	$	(133.5)	$	(467.2)	$	11.5

(1) The gross amount of recognized derivative liabilities is reported with other liabilities on the consolidated statements of financial position. The above excludes derivative liabilities, which are primarily embedded derivatives that are not subject to master netting agreements or similar agreements. The gross amounts of derivative liabilities are not netted against offsetting assets for presentation on the consolidated statements of financial position.

(2) Represents amount of offsetting derivative assets that are subject to an enforceable master netting agreement or similar agreement that are not netted against the gross derivative liabilities for presentation on the consolidated statements of financial position.