Reserve for Loss and Loss Expense (Tables)

9 Months Ended

Sep. 30, 2019

Insurance Loss Reserves [Abstract]

Schedule of Liability for Unpaid Claims and Claims Adjustment Expense

	Nine Months ended September 30,
($ in thousands)	2019			2018
Gross reserve for loss and loss expense, at beginning of year	$	3,893,868		3,771,240
Less: reinsurance recoverable on unpaid loss and loss expense, at beginning of year	537,388			585,855
Net reserve for loss and loss expense, at beginning of year	3,356,480			3,185,385
Incurred loss and loss expense for claims occurring in the:
Current year	1,200,878			1,148,032
Prior years	(34,640		)	(17,564	)
Total incurred loss and loss expense	1,166,238			1,130,468
Paid loss and loss expense for claims occurring in the:
Current year	384,436			369,036
Prior years	631,589			610,734
Total paid loss and loss expense	1,016,025			979,770
Net reserve for loss and loss expense, at end of period	3,506,693			3,336,083
Add: Reinsurance recoverable on unpaid loss and loss expense, at end of period	548,938			589,072
Gross reserve for loss and loss expense at end of period	$	4,055,631		3,925,155