Benefit Plans (Tables)

6 Months Ended

Jun. 30, 2024

Entity Information [Line Items]

Schedule of Net Periodic Benefit Cost / (Income)

The following table presents the net periodic benefit cost of the Pension Plans for the three and six months ended June 30, 2024 and 2023:

	Three months ended				Six months ended
	June 30,				June 30,
$ in millions	2024		2023		2024		2023
Service cost	$	0.6	$	0.7	$	1.2	$	1.4
Interest cost	3.7		4.0		7.4		8.0
Expected return on plan assets	(3.7)		(4.4)		(7.4)		(8.8)
Amortization of unrecognized:
Prior service cost	0.2		0.3		0.5		0.5
Actuarial loss	0.6		0.1		1.1		0.3
Net periodic benefit cost	$	1.4	$	0.7	$	2.8	$	1.4

Subsidiaries [Member]

Entity Information [Line Items]

Schedule of Net Periodic Benefit Cost / (Income)

The following table presents the net periodic benefit cost of the Pension Plans for the three and six months ended June 30, 2024 and 2023:

	Three months ended				Six months ended
	June 30,				June 30,
$ in millions	2024		2023		2024		2023
Service cost	$	0.6	$	0.7	$	1.2	$	1.4
Interest cost	3.7		4.0		7.4		8.0
Expected return on plan assets	(3.7)		(4.4)		(7.4)		(8.8)
Amortization of unrecognized:
Prior service cost	0.2		0.3		0.4		0.6
Actuarial loss	1.0		0.3		2.0		0.6
Net periodic benefit cost	$	1.8	$	0.9	$	3.6	$	1.8