Reserve for Losses and Loss Expenses Reserves for Losses and Loss Expenses (Tables)

3 Months Ended

Mar. 31, 2017

Schedule of Liability for Unpaid Claims and Claims Adjustment Expense [Table Text Block]



	Quarter ended March 31,
($ in thousands)	2017			2016
Gross reserves for losses and loss expenses, at beginning of year	$	3,691,719		3,517,728
Less: reinsurance recoverable on unpaid losses and loss expenses, at beginning of year	611,200			551,019
Net reserves for losses and loss expenses, at beginning of year	3,080,519			2,966,709
Incurred losses and loss expenses for claims occurring in the:
Current year	331,331			312,778
Prior years	(13,859		)	(15,634	)
Total incurred losses and loss expenses	317,472			297,144
Paid losses and loss expenses for claims occurring in the:
Current year	54,708			44,310
Prior years	235,742			212,368
Total paid losses and loss expenses	290,450			256,678
Net reserves for losses and loss expenses, at end of period	3,107,541			3,007,175
Add: Reinsurance recoverable on unpaid losses and loss expenses, at end of period	571,930			568,321
Gross reserves for losses and loss expenses at end of period	$	3,679,471		3,575,496

Prior year development in First Quarter 2017 of $13.9 million was primarily driven by favorable prior year casualty reserve development of $22.4 million in our general liability line of business, partially offset by unfavorable casualty development of $6.0 million in our commercial automobile line of business and $2.0 million in our personal automobile line of business.

Prior year development in First Quarter 2016 of $15.6 million was primarily due to favorable casualty reserve development of $12.0 million in our workers compensation line of business and $11.0 million in our general liability line of business. This was partially offset by unfavorable casualty development of $5.0 million in our commercial automobile line of business and $1.0 million in our E&S segment.

For a discussion of the trends and recent developments impacting these lines, refer to the "Critical Accounting Policies and Estimates" section of Item 7. "Management's Discussion and Analysis of Financial Condition and Results of Operations." in our 2016 Annual Report.