We have three principal operating business segments: Unum US, Unum UK, and Colonial Life. Our other segments are Closed Block and Corporate.

Business Acquired

On September 3, 2015, we acquired 100 percent of the common shares and voting interests in National Dental Plan Limited and associated companies (National Dental) for a total cash purchase price of £35.9 million or $54.3 million. National Dental, a provider of dental insurance in the U.K. workplace, is reported in our Unum UK segment as part of our supplemental product line. The acquisition of National Dental extends our market reach, broadening our employee benefit offerings. National Dental's revenues totaled £14.7 million, or $24.2 million, in 2014. Total assets were £18.6 million, or $28.1 million at the acquisition date, and were primarily comprised of short-term investments, accounts receivable, and intangible assets attributable to benefits derived from National Dental's customer relationships and dental provider network. Total liabilities were £5.0 million, or $7.5 million at the acquisition date, and were primarily comprised of outstanding claims liabilities, unearned premiums, and a deferred tax liability. The purchase price exceeded the fair value of the identifiable net assets by £22.3 million, or $33.7 million, and has been identified as goodwill, primarily attributable to the value of adding dental to our current employee benefit offerings. The goodwill is not deductible for income tax purposes except upon disposition of the acquired entity. This acquisition, the results of which are included in our consolidated financial statements for the period subsequent to the date of acquisition, is not expected to have a material impact on revenue or results of operations during 2015.

Segment information is as follows:



	Three Months Ended September 30				Nine Months Ended September 30
	2015		2014		2015		2014
	(in millions of dollars)
Premium Income
Unum US
Group Disability
Group Long-term Disability	$	414.3	$	387.7	$	1,229.0	$	1,157.4
Group Short-term Disability	153.2		138.3		452.5		413.4
Group Life and Accidental Death & Dismemberment
Group Life	336.5		316.1		1,007.5		939.2
Accidental Death & Dismemberment	32.1		32.2		98.0		93.9
Supplemental and Voluntary
Individual Disability	119.6		116.9		355.9		348.8
Voluntary Benefits	186.1		171.5		565.5		520.2
	1,241.8		1,162.7		3,708.4		3,472.9
Unum UK
Group Long-term Disability	100.6		104.5		296.5		313.4
Group Life	29.7		34.1		90.6		102.6
Supplemental	14.3		14.0		38.7		42.3
	144.6		152.6		425.8		458.3
Colonial Life
Accident, Sickness, and Disability	196.5		190.7		591.1		569.0
Life	62.5		57.9		188.1		172.8
Cancer and Critical Illness	74.1		70.8		222.0		210.8
	333.1		319.4		1,001.2		952.6
Closed Block
Individual Disability	142.2		154.0		433.0		472.9
Long-term Care	158.6		158.3		475.0		471.9
All Other	0.5		0.2		1.2		0.7
	301.3		312.5		909.2		945.5
Total Premium Income	$	2,020.8	$	1,947.2	$	6,044.6	$	5,829.3



	Unum US		Unum UK		Colonial Life		Closed Block		Corporate			Total
	(in millions of dollars)
Three Months Ended September 30, 2015

Premium Income	$	1,241.8	$	144.6	$	333.1	$	301.3	$	—		$	2,020.8
Net Investment Income	214.3		28.0		35.9		327.5		6.4			612.1
Other Income	28.1		—		0.1		21.5		1.8			51.5
Operating Revenue	$	1,484.2	$	172.6	$	369.1	$	650.3	$	8.2		$	2,684.4

Operating Income (Loss)	$	218.7	$	32.7	$	76.3	$	27.7	$	(26.9	)	$	328.5

Three Months Ended September 30, 2014

Premium Income	$	1,162.7	$	152.6	$	319.4	$	312.5	$	—		$	1,947.2
Net Investment Income	214.4		34.4		35.5		317.2		9.8			611.3
Other Income	30.2		—		0.1		23.4		0.9			54.6
Operating Revenue	$	1,407.3	$	187.0	$	355.0	$	653.1	$	10.7		$	2,613.1

Operating Income (Loss)	$	212.1	$	33.5	$	71.0	$	25.7	$	(25.1	)	$	317.2



	Unum US		Unum UK		Colonial Life		Closed Block		Corporate			Total
	(in millions of dollars)
Nine Months Ended September 30, 2015

Premium Income	$	3,708.4	$	425.8	$	1,001.2	$	909.2	$	—		$	6,044.6
Net Investment Income	645.0		90.1		109.8		979.6		20.3			1,844.8
Other Income	90.4		—		0.1		67.5		2.6			160.6
Operating Revenue	$	4,443.8	$	515.9	$	1,111.1	$	1,956.3	$	22.9		$	8,050.0

Operating Income (Loss)	$	635.8	$	103.6	$	231.5	$	91.0	$	(90.2	)	$	971.7

Nine Months Ended September 30, 2014

Premium Income	$	3,472.9	$	458.3	$	952.6	$	945.5	$	—		$	5,829.3
Net Investment Income	655.7		112.3		107.9		958.5		25.1			1,859.5
Other Income	91.4		0.1		0.1		69.5		2.2			163.3
Operating Revenue	$	4,220.0	$	570.7	$	1,060.6	$	1,973.5	$	27.3		$	7,852.1

Operating Income (Loss)	$	635.4	$	109.6	$	225.0	$	90.6	$	(80.0	)	$	980.6



	September 30		December 31
	2015		2014
	(in millions of dollars)
Assets
Unum US	$	18,630.7	$	18,676.5
Unum UK	3,636.3		3,702.5
Colonial Life	3,770.3		3,692.2
Closed Block	33,431.9		33,960.2
Corporate	2,034.6		2,418.8
Total Assets	$	61,503.8	$	62,450.2

We measure and analyze our segment performance using non-GAAP financial measures. A non-GAAP financial measure is a numerical measure of a company's performance, financial position, or cash flows that excludes or includes amounts that are not normally excluded or included in the most directly comparable measure calculated and presented in accordance with GAAP. The non-GAAP financial measures of "operating revenue" and "operating income" or "operating loss" differ from total revenue and income before income tax as presented in our consolidated statements of income due to the exclusion of net realized investment gains and losses, non-operating retirement-related gains or losses, and costs related to early retirement of debt as specified in the reconciliations below. We believe operating revenue and operating income or loss are better performance measures and better indicators of the revenue and profitability and underlying trends in our business.

Realized investment gains or losses depend on market conditions and do not necessarily relate to decisions regarding the underlying business of our segments. Our investment focus is on investment income to support our insurance liabilities as opposed to the generation of realized investment gains or losses. Although we may experience realized investment gains or losses which will affect future earnings levels, a long-term focus is necessary to maintain profitability over the life of the business since our underlying business is long-term in nature, and we need to earn the interest rates assumed in calculating our liabilities.

The amortization of prior period actuarial gains or losses, a component of the net periodic benefit cost for our pensions and other postretirement benefit plans, is driven by market performance as well as plan amendments and is not indicative of the operational results of our businesses. We believe that excluding the amortization of prior period gains or losses from operating income or loss provides investors with additional information for comparison and analysis of our operating results. Although we manage our non-operating retirement-related gains or losses separately from the operational performance of our business, these gains or losses impact the overall profitability of our company and have historically increased or decreased over time, depending on plan amendments and market conditions and the resulting impact on the actuarial gains or losses in our pensions and other postretirement benefit plans.

We believe that excluding the costs related to the early retirement of debt that occurred in the second quarter of 2014 is appropriate because in conjunction with the debt redemption, we recognized in realized investment gains and losses a deferred gain from previously terminated derivatives which were associated with the hedge of this debt. The amount recognized as a realized investment gain, which basically offsets the cost of the debt redemption, is also excluded from our non-GAAP financial measures since we analyze our performance excluding amounts reported as realized investment gains or losses. We believe it provides investors with a more realistic view of our overall profitability if we are consistent in excluding both the cost of the debt retirement as well as the gain on the hedge of the debt.

We may at other times exclude certain other items from our discussion of financial ratios and metrics in order to enhance the understanding and comparability of our operational performance and the underlying fundamentals, but this exclusion is not an indication that similar items may not recur and does not replace net income or net loss as a measure of our overall profitability.

A reconciliation of "operating revenue" to total revenue and "operating income" to income before income tax is as follows:



	Three Months Ended September 30						Nine Months Ended September 30
	2015			2014			2015			2014
	(in millions of dollars)
Operating Revenue	$	2,684.4		$	2,613.1		$	8,050.0		$	7,852.1
Net Realized Investment Gain (Loss)	(26.6		)	1.2			(41.1		)	33.4
Total Revenue	$	2,657.8		$	2,614.3		$	8,008.9		$	7,885.5

Operating Income	$	328.5		$	317.2		$	971.7		$	980.6
Net Realized Investment Gain (Loss)	(26.6		)	1.2			(41.1		)	33.4
Non-operating Retirement-related Loss	(3.0		)	(1.4		)	(8.9		)	(4.2		)
Costs Related to Early Retirement of Debt	—			—			—			(13.2		)
Income Before Income Tax	$	298.9		$	317.0		$	921.7		$	996.6