Goodwill and Other Intangible Assets (Tables)

9 Months Ended

Sep. 30, 2024

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of intangible assets and goodwill

The following table presents the economic lives, acquisition date fair values, accumulated amortization and net carrying values for other intangible assets and goodwill as of September 30, 2024 and December 31, 2023:

$ in Millions	Weighted Average Economic  Life (in years)	September 30, 2024						December 31, 2023
		Acquisition Date Fair Value		Accumulated Amortization		Net Carrying Value		Acquisition Date Fair Value		Accumulated Amortization		Net Carrying Value
Goodwill:
Ark	N/A	$	116.8	$	—	$	116.8	$	116.8	$	—	$	116.8
Kudu	N/A	7.6		—		7.6		7.6		—		7.6
Bamboo (1)	N/A	270.4		—		270.4		—		—		—
Other Operations	N/A	44.4		—		44.4		44.4		—		44.4
Total goodwill		439.2		—		439.2		168.8		—		168.8
Other intangible assets:
Ark
Underwriting capacity	N/A	175.7		—		175.7		175.7		—		175.7
Kudu
Trade names	7.0	2.2		1.8		.4		2.2		1.5		.7
Bamboo (1)
Trade names	10.0	23.5		1.8		21.7		—		—		—
Agency relationships	6.0	72.4		9.1		63.3		—		—		—
Developed technology	3.0	4.7		1.1		3.6		—		—		—
Other	0.3	.4		.4		—		—		—		—
Subtotal		101.0		12.4		88.6		—		—		—
Other Operations
Trade names	13.3	13.3		5.3		8.0		13.3		4.1		9.2
Customer relationships	11.0	24.8		12.7		12.1		24.8		10.3		14.5
Other	11.8	3.1		1.4		1.7		2.8		1.1		1.7
Subtotal		41.2		19.4		21.8		40.9		15.5		25.4
Total other intangible assets		320.1		33.6		286.5		218.8		17.0		201.8
Total goodwill and other intangible assets		$	759.3	$	33.6	$	725.7	$	387.6	$	17.0	$	370.6

(1) The relative fair values of goodwill and other intangible assets recognized in connection with the acquisition of Bamboo had not yet been finalized as of September 30, 2024.

The following tables present the change in goodwill and other intangible assets for the three and nine months ended September 30, 2024 and 2023:

	Three Months Ended September 30,
	2024						2023
Millions	Goodwill		Other Intangible Assets		Total Goodwill and Other Intangible Assets		Goodwill		Other Intangible Assets		Total Goodwill and Other Intangible Assets
Beginning balance	$	439.2	$	291.8	$	731.0	$	168.8	$	204.8	$	373.6
Amortization	—		(5.3)		(5.3)		—		(1.5)		(1.5)
Ending balance	$	439.2	$	286.5	$	725.7	$	168.8	$	203.3	$	372.1

	Nine Months Ended September 30,
	2024						2023
Millions	Goodwill		Other Intangible Assets		Total Goodwill and Other Intangible Assets		Goodwill		Other Intangible Assets		Total Goodwill and Other Intangible Assets
Beginning balance	$	168.8	$	201.8	$	370.6	$	176.5	$	215.9	$	392.4
Acquisition of businesses (1)	270.4		101.0		371.4		—		—		—
Acquisitions of intangible assets (2)	—		.3		.3		—		—		—
Dispositions (2)	—		—		—		(6.7)		(6.9)		(13.6)
Measurement period adjustments (3)	—		—		—		(1.0)		—		(1.0)
Amortization	—		(16.6)		(16.6)		—		(5.7)		(5.7)
Ending balance	$	439.2	$	286.5	$	725.7	$	168.8	$	203.3	$	372.1

(1) Amounts relate to the fair values of goodwill and other intangible assets recognized in connection with the acquisition of Bamboo, which had not yet been finalized as of September 30, 2024.

(2) Relates to acquisitions and dispositions within Other Operations.

(3) Measurement period adjustments relate to updated information about acquisition date fair values of assets acquired and liabilities assumed. During the nine

months ended September 30, 2023, adjustments relate to an acquisition within Other Operations.