Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2019

Commitments And Contingencies Disclosure [Abstract]

Consolidated Lease Liabilities And Right-Of-Use Lease Assets Related To Operating Leases

The following table presents Alleghany’s consolidated lease liabilities and right-of-use lease assets related to operating leases as of December 31, 2019

	As of December 31, 2019
Maturity of lease payments, by year	($ in millions)
1 year or less	$	39.0
More than 1 year to 2 years		36.5
More than 2 years to 3 years		28.9
More than 3 years to 4 years		27.2
More than 4 years to 5 years		24.8
More than 5 years		145.2
Total lease payments(1)		301.6
Less: interest(2)		(60.5	)
Lease liabilities(3)	$	241.1
Right-of-use lease assets(4)	$	209.7
Prepaid lease assets, net of lease allowances and incentives		31.4
	$	241.1

(1) As of December 31, 2019, the weighted average lease term was approximately 12 years.

(2) As of December 31, 2019, the weighted average discount rate was approximately 5 percent.

(3) Represents the present value of lease liabilities and is reported as a component of other liabilities on Alleghany’s consolidated balance sheet.

(4)         Reported as a component of other assets on Alleghany’s consolidated balance sheet.

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

The following table presents such gross and net reserves as of December 31, 2019 and 2018:

	December 31, 2019				December 31, 2018
	Gross		Net		Gross		Net
	($ in millions)
TransRe	$	113.0	$	108.3	$	128.1	$	124.6
CapSpecialty		4.8		4.8		5.6		5.6
Total	$	117.8	$	113.1	$	133.7	$	130.2