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

Segment information is as follows:



	Three Months Ended September 30				Nine Months Ended September 30
	2017		2016		2017		2016
	(in millions of dollars)
Premium Income
Unum US
Group Disability
Group Long-term Disability	$	435.2	$	428.1	$	1,307.3	$	1,291.6
Group Short-term Disability	161.1		155.5		477.3		469.2
Group Life and Accidental Death & Dismemberment
Group Life	370.0		353.4		1,101.7		1,053.6
Accidental Death & Dismemberment	37.2		35.3		110.5		104.8
Supplemental and Voluntary
Individual Disability	104.4		125.6		318.1		374.4
Voluntary Benefits	210.8		197.1		639.2		602.1
Dental and Vision	42.2		20.0		124.9		20.0
	1,360.9		1,315.0		4,079.0		3,915.7
Unum UK
Group Long-term Disability	87.0		85.5		251.6		274.1
Group Life	26.7		24.9		76.9		80.9
Supplemental	17.8		16.9		51.1		52.4
	131.5		127.3		379.6		407.4
Colonial Life
Accident, Sickness, and Disability	222.3		207.7		661.5		619.2
Life	74.6		68.0		223.8		203.4
Cancer and Critical Illness	81.8		78.4		244.0		234.1
	378.7		354.1		1,129.3		1,056.7
Closed Block
Individual Disability	117.9		129.9		357.7		394.0
Long-term Care	162.4		161.4		486.4		482.0
All Other	2.2		1.7		6.7		2.7
	282.5		293.0		850.8		878.7
Total Premium Income	$	2,153.6	$	2,089.4	$	6,438.7	$	6,258.5



	Unum US		Unum UK		Colonial Life		Closed Block		Corporate			Total
	(in millions of dollars)
Three Months Ended September 30, 2017
Premium Income	$	1,360.9	$	131.5	$	378.7	$	282.5	$	—		$	2,153.6
Net Investment Income	201.0		28.5		36.0		337.2		6.3			609.0
Other Income	26.5		0.6		0.3		18.9		0.4			46.7
Operating Revenue	$	1,588.4	$	160.6	$	415.0	$	638.6	$	6.7		$	2,809.3

Operating Income (Loss)	$	258.4	$	26.5	$	81.7	$	26.6	$	(36.2	)	$	357.0

Three Months Ended September 30, 2016
Premium Income	$	1,315.0	$	127.3	$	354.1	$	293.0	$	—		$	2,089.4
Net Investment Income	207.3		28.5		36.1		334.1		5.4			611.4
Other Income	28.7		—		0.4		21.5		0.9			51.5
Operating Revenue	$	1,551.0	$	155.8	$	390.6	$	648.6	$	6.3		$	2,752.3

Operating Income (Loss)	$	231.0	$	28.2	$	79.0	$	28.6	$	(45.7	)	$	321.1



	Unum US		Unum UK		Colonial Life		Closed Block		Corporate			Total
	(in millions of dollars)
Nine Months Ended September 30, 2017
Premium Income	$	4,079.0	$	379.6	$	1,129.3	$	850.8	$	—		$	6,438.7
Net Investment Income	609.1		88.3		107.8		1,012.5		14.2			1,831.9
Other Income	85.3		0.6		0.8		59.9		1.5			148.1
Operating Revenue	$	4,773.4	$	468.5	$	1,237.9	$	1,923.2	$	15.7		$	8,418.7

Operating Income (Loss)	$	745.3	$	82.0	$	245.9	$	90.8	$	(113.6	)	$	1,050.4

Nine Months Ended September 30, 2016
Premium Income	$	3,915.7	$	407.4	$	1,056.7	$	878.7	$	—		$	6,258.5
Net Investment Income	622.4		89.3		105.7		1,008.6		15.1			1,841.1
Other Income	85.6		0.2		1.0		65.3		2.5			154.6
Operating Revenue	$	4,623.7	$	496.9	$	1,163.4	$	1,952.6	$	17.6		$	8,254.2

Operating Income (Loss)	$	674.1	$	98.7	$	234.3	$	94.9	$	(121.3	)	$	980.7



	September 30		December 31
	2017		2016
	(in millions of dollars)
Assets
Unum US	$	18,069.2	$	18,036.6
Unum UK	3,422.9		3,101.4
Colonial Life	4,099.4		3,923.2
Closed Block	34,717.0		33,734.3
Corporate	3,497.2		3,146.0
Total Assets	$	63,805.7	$	61,941.5

We measure and analyze our segment performance on the basis of "operating revenue" and "operating income" or "operating loss", which 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 and certain other items 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. These performance measures are in accordance with GAAP guidance for segment reporting, but they should not be viewed as a substitute for total revenue, income before income tax, or net income.

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.

We previously excluded the amortization of prior period actuarial gains or losses, a component of the net periodic benefit cost for our pension and other postretirement benefit plans. Effective January 1, 2017, the amortization of prior period actuarial gains or losses is now reported as a component of "operating income" in the following chart. Amounts for periods prior to January 1, 2017 have been adjusted to conform to current year reporting.

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. See Note 11 for further discussion regarding the loss from a guaranty fund assessment.

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



	Three Months Ended September 30				Nine Months Ended September 30
	2017		2016		2017			2016
	(in millions of dollars)
Total Revenue	$	2,819.1	$	2,763.3	$	8,447.6		$	8,250.0
Excluding:
Net Realized Investment Gain (Loss)	9.8		11.0		28.9			(4.2		)
Operating Revenue	$	2,809.3	$	2,752.3	$	8,418.7		$	8,254.2

Income Before Income Tax	$	366.8	$	332.1	$	1,058.7		$	976.5
Excluding:
Net Realized Investment Gain (Loss)	9.8		11.0		28.9			(4.2		)
Loss from Guaranty Fund Assessment	—		—		(20.6		)	—
Operating Income	$	357.0	$	321.1	$	1,050.4		$	980.7