Goodwill and Other Intangible Assets (Tables)

3 Months Ended

Mar. 31, 2023

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 March 31, 2023 and December 31, 2022:

$ in Millions	Weighted Average Economic  Life (in years)	March 31, 2023						December 31, 2022
		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
Other Operations	N/A	44.4		—		44.4		52.1		—		52.1
Total goodwill		168.8		—		168.8		176.5		—		176.5
Other intangible assets:
Ark
Underwriting capacity	N/A	175.7		—		175.7		175.7		—		175.7
Kudu
Trade names	7	2.2		1.3		.9		2.2		1.2		1.0
Other Operations
Trade names	13.3	13.3		2.6		10.7		17.9		3.0		14.9
Customer relationships	11.0	24.8		7.0		17.8		29.5		7.5		22.0
Other	12.1	2.8		.5		2.3		2.8		.5		2.3
Subtotal		40.9		10.1		30.8		50.2		11.0		39.2
Total other intangible assets		218.8		11.4		207.4		228.1		12.2		215.9
Total goodwill and other intangible assets		$	387.6	$	11.4	376.2		$	404.6	$	12.2	392.4

The following table presents the change in goodwill and other intangible assets for the three months ended March 31, 2023 and 2022:

	Three Months Ended March 31,
	2023						2022
Millions	Goodwill		Other Intangible Assets		Total Goodwill and Other Intangible Assets		Goodwill		Other Intangible Assets		Total Goodwill and Other Intangible Assets
Beginning balance	$	176.5	$	215.9	$	392.4	$	142.3	$	198.2	$	340.5
Dispositions (1)	(6.7)		(6.9)		(13.6)		—		—		—
Measurement period adjustments (2)	(1.0)		—		(1.0)		—		—		—
Amortization	—		(1.6)		(1.6)		—		(1.0)		(1.0)
Ending balance	$	168.8	$	207.4	$	376.2	$	142.3	$	197.2	$	339.5

(1) Relates to a disposition within Other Operations.

(2) Measurement period adjustments relate to updated information about acquisition date fair values of assets acquired and liabilities assumed. During the three months ended March 31, 2023 adjustments relate to an acquisition within Other Operations. The relative fair values of goodwill and other intangible assets recognized in connection with this acquisition during 2022 had not yet been finalized as of the end of the period.