Losses and Loss Expenses Payable (Tables)

12 Months Ended

Dec. 31, 2018

Insurance [Abstract]

Schedule of Activity in Liability for Losses and Loss Expenses

The following table sets forth the activity in the liability for losses and loss expenses for the years ended December 31:

($ millions)	2018		2017		2016
Losses and loss expenses payable, at beginning of year	$	1,255.6	$	1,181.6	$	1,053.0
Less: reinsurance recoverable on losses and loss expenses payable	3.1		3.6		5.9
Net balance at beginning of year	1,252.5		1,178.0		1,047.1
Incurred related to:
Current year	876.6		964.9		915.3
Prior years	(80.2)		(46.6)		27.0
Total incurred	796.4		918.3		942.3
Paid related to:
Current year	456.5		445.2		417.7
Prior years	451.1		398.6		393.7
Total paid	907.6		843.8		811.4
Net balance at end of year	1,141.3		1,252.5		1,178.0
Plus: reinsurance recoverable on losses and loss expenses payable	5.5		3.1		3.6
Losses and loss expenses payable (affiliated net assumed $593.6, $711.4, and $630.9 respectively)	$	1,146.8	$	1,255.6	$	1,181.6