The Company’s primary business operations include insurance products and services provided through three operating segments: Commercial Lines, Personal Lines and Other. Commercial Lines includes commercial multiple peril, commercial automobile, workers’ compensation, and other commercial coverages, such as management and professional liability, marine, Hanover Programs, specialty industrial and commercial property, monoline general liability and surety. Personal Lines includes personal automobile, homeowners and other personal coverages. Included in the Other segment are Opus Investment Management, Inc., which markets investment management services to institutions, pension funds and other organizations; earnings on holding company assets; holding company and other expenses, including certain costs associated with retirement benefits due to the Company’s former life insurance employees and agents; and, a run-off property and casualty voluntary pools business. On December 28, 2018, the Company completed the sale of Chaucer to China Re, and the sales of the Chaucer-related Irish and Australian entities were subsequently completed on February 14, 2019 and April 10, 2019, respectively. Accordingly, as of December 31, 2018, and for all prior periods, Chaucer’s results of operations are classified as Discontinued Operations in the Consolidated Statements of Income and assets and liabilities related to the Chaucer business have been classified as held-for-sale in the Consolidated Balance Sheet at December 31, 2018 (see Note 2 – “Discontinued Operations”). Certain ongoing expenses have been reclassified from Chaucer to the other three operating segments. The separate financial information is presented consistent with the way results are regularly evaluated by the chief operating decision maker in deciding how to allocate resources and in assessing performance.

The Company reports interest expense related to debt separately from the earnings of its operating segments. For 2019, this consisted of interest on the Company’s senior and subordinated debentures.

Management evaluates the results of the aforementioned segments based on operating income before taxes, excluding interest expense on debt. Operating income before taxes excludes certain items which are included in net income, such as net realized and unrealized investment gains (losses). Such gains and losses are excluded since they are determined by interest rates, financial markets and the timing of sales. Also, operating income before taxes excludes net gains and losses on disposals of businesses, gains and losses related to the repayment of debt, discontinued operations, costs to acquire businesses, restructuring costs, the cumulative effect of accounting changes and certain other items. Although the items excluded from operating income before taxes may be important components in understanding and assessing the Company’s overall financial performance, management believes that the presentation of operating income before taxes enhances an investor’s understanding of the Company’s results of operations by highlighting net income attributable to the core operations of the business. However, operating income before taxes should not be construed as a substitute for income before income taxes or income from continuing operations and operating income should not be construed as a substitute for net income.

Summarized below is financial information with respect to the Company’s business segments.

YEARS ENDED DECEMBER 31	2019			2018			2017
(in millions)
Operating revenues:
Commercial Lines	$	2,843.5		$	2,739.5		$	2,573.8
Personal Lines		1,911.8			1,791.3			1,662.3
Other		26.0			14.2			10.7
Total		4,781.3			4,545.0			4,246.8
Net realized and unrealized investment gains (losses)		109.4			(50.7	)		21.1
Total revenues	$	4,890.7		$	4,494.3		$	4,267.9
Operating income (loss) before interest expense and income taxes:
Commercial Lines:
Underwriting income	$	121.5		$	85.0		$	12.2
Net investment income		180.1			182.2			165.8
Other expense		(1.5	)		(1.5	)		(0.6	)
Commercial Lines operating income		300.1			265.7			177.4
Personal Lines:
Underwriting income		59.1			66.6			83.7
Net investment income		80.1			73.7			70.1
Other income		5.7			5.9			4.9
Personal Lines operating income		144.9			146.2			158.7
Other:
Underwriting loss		(1.3	)		(4.2	)		(4.2	)
Net investment income		21.1			11.5			8.0
Other expense		(11.2	)		(12.7	)		(12.6	)
Other operating income (loss)		8.6			(5.4	)		(8.8	)
Operating income before interest expense and income taxes		453.6			406.5			327.3
Interest on debt		(37.5	)		(45.1	)		(45.2	)
Operating income before income taxes		416.1			361.4			282.1
Non-operating income (loss) items:
Net realized and unrealized investment gains (losses)		109.4			(50.7	)		21.1
Net loss from repayment of debt		—			(28.2	)		—
Other non-operating items		(3.4	)		—			(10.3	)
Income from continuing operations before income taxes	$	522.1		$	282.5		$	292.9

The following table provides identifiable assets for the Company’s business segments and discontinued operations:

The Company reviews the assets of its Property and Casualty Companies collectively and does not allocate them among the Commercial Lines, Personal Lines and Other segments.