Losses and Loss Expenses Payable Losses and Loss Expenses Payable (Tables)

9 Months Ended

Sep. 30, 2017

Losses and Loss Expenses Payable [Abstract]

Schedule Of Activity In Liability For Unpaid Losses And Loss Adjustment Expenses Table [Table Text Block]

($ millions)	2017			2016
Losses and loss expenses payable, at beginning of period	$	1,181.6		$	1,053.0
Less: reinsurance recoverable on losses and loss expenses payable	3.6			5.9
Net balance at beginning of period	1,178.0			1,047.1
Incurred related to:
Current year	752.5			686.8
Prior years	(34.6		)	33.4
Total incurred	717.9			720.2
Paid related to:
Current year	302.0			286.6
Prior years	318.3			319.2
Total paid	620.3			605.8
Net balance at end of period	1,275.6			1,161.5
Plus: reinsurance recoverable on losses and loss expenses payable	4.9			4.1
Losses and loss expenses payable, at end of period	$	1,280.5		$	1,165.6