Benefit Plans (Tables)

6 Months Ended

Jun. 30, 2022

Entity Information [Line Items]

Schedule of Net Periodic Benefit Cost / (Income)

The net periodic benefit cost of the pension benefit plans for the three and six months ended June 30, 2022 and 2021 was:

	Three months ended				Six months ended
	June 30,				June 30,
$ in millions	2022		2021		2022		2021
Service cost	$	1.2	$	1.1	$	2.5	$	2.2
Interest cost	2.4		2.0		4.8		4.0
Expected return on plan assets	(3.9)		(3.7)		(7.9)		(7.4)
Amortization of unrecognized:
Prior service cost	0.3		0.2		0.5		0.4
Actuarial loss	1.3		2.3		2.7		4.6
Net periodic benefit cost	$	1.3	$	1.9	$	2.6	$	3.8

Subsidiaries [Member]

Entity Information [Line Items]

Schedule of Net Periodic Benefit Cost / (Income)

The net periodic benefit cost of the pension benefit plans for the three and six months ended June 30, 2022 and 2021 was:

	Three months ended				Six months ended
	June 30,				June 30,
$ in millions	2022		2021		2022		2021
Service cost	$	1.2	$	1.1	$	2.5	$	2.2
Interest cost	2.4		2.0		4.8		4.0
Expected return on plan assets	(3.9)		(3.7)		(7.9)		(7.4)
Amortization of unrecognized:
Prior service cost	0.3		0.3		0.6		0.6
Actuarial loss	1.9		2.8		3.8		5.6
Net periodic benefit cost	$	1.9	$	2.5	$	3.8	$	5.0