Reinsurance (Tables)

9 Months Ended

Sep. 30, 2020

Insurance [Abstract]

Summary of External Reinsurance Transactions with State Auto Mutual Under Pooling Arrangement

The following table sets forth a summary of the Company’s external reinsurance transactions, as well as reinsurance transactions with State Auto Mutual under the Pooling Arrangement, for the three and nine months ended September 30, 2020 and 2019:

($ millions)	Three months ended September 30				Nine months ended September 30
	2020		2019		2020		2019
Premiums earned:
Assumed from external insurers and reinsurers	$	21.7	$	21.0	$	63.0	$	59.3
Assumed under Pooling Arrangement	353.2		319.6		1,024.4		930.0
Ceded to external insurers and reinsurers	(7.7)		(6.6)		(25.4)		(18.8)
Ceded under Pooling Arrangement	(283.9)		(263.9)		(835.2)		(761.5)
Net assumed premiums earned	$	83.3	$	70.1	$	226.8	$	209.0
Losses and loss expenses incurred:
Assumed from external insurers and reinsurers	$	14.1	$	14.6	$	41.3	$	45.6
Assumed under Pooling Arrangement	251.6		209.3		762.2		639.4
Ceded to external insurers and reinsurers	(9.9)		(0.6)		(55.9)		(6.2)
Ceded under Pooling Arrangement	(202.9)		(185.1)		(629.4)		(514.3)
Net assumed losses and loss expenses incurred	$	52.9	$	38.2	$	118.2	$	164.5