Segment Information

The results of our four reportable segments are evaluated as follows:


•	Our Standard Commercial Lines, Standard Personal Lines, and Excess and Surplus ("E&S") Lines are evaluated based on before and after-tax underwriting results (net premiums earned, incurred loss and loss expense, policyholder dividends, policy acquisition costs, and other underwriting expenses), return on equity ("ROE") contribution, and combined ratios.


•	Our Investments segment is primarily evaluated based on after-tax net investment income and its ROE contribution. Also included in Investment segment results are after-tax net realized and unrealized gains and losses, which are not included in non-GAAP operating income.

In computing the results of each segment, we do not make adjustments for interest expense or corporate expenses. We do not maintain separate investment portfolios for the segments and therefore, do not allocate assets to the segments.

The following summaries present revenues (net investment income and net realized and unrealized gains on investments in the case of the Investments segment) and pre-tax income for the individual segments:



Revenue by Segment	Quarter ended March 31,
($ in thousands)	2019		2018
Standard Commercial Lines:
Net premiums earned:
Commercial automobile	$	131,186	118,231
Workers compensation	78,715		78,823
General liability	161,525		149,829
Commercial property	86,067		80,326
Businessowners’ policies	26,081		25,591
Bonds	8,904		8,134
Other	4,706		4,430
Miscellaneous income	2,044		1,826
Total Standard Commercial Lines revenue	499,228		467,190
Standard Personal Lines:
Net premiums earned:
Personal automobile	43,163		40,442
Homeowners	32,130		32,201
Other	2,014		1,613
Miscellaneous income	276		352
Total Standard Personal Lines revenue	77,583		74,608
E&S Lines:
Net premiums earned:
Casualty lines	44,528		38,540
Property lines	13,554		13,668
Miscellaneous income	—		1
Total E&S Lines revenue	58,082		52,209
Investments:
Net investment income	50,618		43,231
Net realized and unrealized investment gains (losses)	13,451		(10,549	)
Total Investments revenue	64,069		32,682
Total revenues	$	698,962	626,689



Income Before and After Federal Income Tax	Quarter ended March 31,
($ in thousands)	2019			2018
Standard Commercial Lines:
Underwriting gain, before federal income tax	$	25,815		6,804
Underwriting gain, after federal income tax	20,394			5,375
Combined ratio	94.8		%	98.5
ROE contribution	4.4			1.3

Standard Personal Lines:
Underwriting gain (loss), before federal income tax	$	3,167		(1,506	)
Underwriting gain (loss), after federal income tax	2,502			(1,190	)
Combined ratio	95.9		%	102.0
ROE contribution	0.5			(0.3	)

E&S Lines:
Underwriting gain (loss), before federal income tax	$	4,579		(565	)
Underwriting gain (loss), after federal income tax	3,617			(446	)
Combined ratio	92.1		%	101.1
ROE contribution	0.8			(0.1	)

Investments:
Net investment income	$	50,618		43,231
Net realized and unrealized investment gains (losses)	13,451			(10,549	)
Total investment segment income, before federal income tax	64,069			32,682
Tax on investment segment income	12,120			5,226
Total investment segment income, after federal income tax	$	51,949		27,456
ROE contribution of after-tax net investment income	8.9			8.5



Reconciliation of Segment Results to Income Before Federal Income Tax	Quarter ended March 31,
($ in thousands)	2019			2018
Underwriting gain (loss)
Standard Commercial Lines	$	25,815		6,804
Standard Personal Lines	3,167			(1,506	)
E&S Lines	4,579			(565	)
Investment income	64,069			32,682
Total all segments	97,630			37,415
Interest expense	(11,526		)	(6,152	)
Corporate expenses	(12,410		)	(11,332	)
Income, before federal income tax	$	73,694		19,931