Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2017

Aggregate Minimum Payments under Operating Leases with Initial or Remaining Terms of More Than One Year

The following table presents the aggregate minimum payments under operating leases with initial or remaining terms of more than one year as of December 31, 2017:

Year	Aggregate Minimum Lease Payments
	($ in millions)
2018	$	37.4
2019		35.7
2020		31.4
2021		29.3
2022		23.2
2023 and thereafter		156.7

Asbestos Related Illnesses and Environmental Impairment Loss and Loss Adjustment Expense Reserves

Loss and LAE include amounts for risks relating to asbestos-related illness and environmental impairment. The following table presents such gross and net reserves as of December 31, 2017 and 2016:

	December 31, 2017				December 31, 2016
	Gross		Net		Gross		Net
	($ in millions)
TransRe	$	152.4	$	148.0	$	165.7	$	160.0
CapSpecialty		6.0		6.0		6.3		6.3
Total	$	158.4	$	154.0	$	172.0	$	166.3