Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2023

Accounting policies and error corrections [Abstract]

New Accounting Pronouncements and Changes in Accounting Principles

The following table summarizes the changes in stockholders' equity due to the adoption of ASU 2018-12 and the resulting adjusted balances at January 1, 2021:

	Consolidated
	Retained Earnings		Accumulated Other Comprehensive Income (Loss)		Total Stockholders' Equity
	(in millions of dollars)
Balance at December 31, 2020	$	11,269.6	$	374.2	$	10,871.0
Impact of the Adoption of ASU 2018-12	(20.6)		(6,684.4)		(6,705.0)
Balance at January 1, 2021	$	11,249.0	$	(6,310.2)	$	4,166.0

The following tables summarize the changes in the liability for future policy benefits due to the adoption of ASU 2018-12 and the resulting adjusted balance at January 1, 2021. The removal of shadow adjustments and effect of change in discount rate assumptions are both recorded as transition adjustments to accumulated other comprehensive income (loss) (AOCI) while the adjustments for loss contracts are recorded as a transition adjustment to retained earnings.

	Unum US		Unum International		Colonial Life		Closed Block		Consolidated
	(in millions of dollars)
Balance at December 31, 20201	$	12,184.6	$	2,969.8	$	1,977.2	$	28,572.8	$	45,704.4
Removal of Shadow Adjustments2	(1,569.7)		(545.8)		(44.5)		(4,065.6)		(6,225.6)
Adjustments for Loss Contracts3	—		—		34.9		—		34.9
Effect of Change in Discount Rate Assumptions	2,251.8		779.4		568.6		12,484.8		16,084.6
Other4	(5.3)		—		(7.6)		—		(12.9)
Balance at January 1, 2021	12,861.4		3,203.4		2,528.6		36,992.0		55,585.4
Reinsurance Recoverable5	357.7		132.5		4.4		10,001.4		10,496.0
Balance, Net of Reinsurance, at January 1, 2021	$	12,503.7	$	3,070.9	$	2,524.2	$	26,990.6	$	45,089.4
1We previously reported policy and contract benefits and reserves for future policy and contract benefits liabilities in our consolidated balance sheet as of December 31, 2020 of $1,855.4 million and $49,653.0 million, respectively, resulting in total policyholder liabilities of $51,508.4 million. These balances were reclassified into new line items, future policy benefits and policyholders' account balances, which would have reported balances of $45,704.4 million and $5,804.0 million as of December 31, 2020, respectively, resulting in total policyholder liabilities of $51,508.4 million under the historical accounting method. These balances were reclassified to more closely align with the new disclosure requirements of ASU 2018-12.
2Shadow adjustments represent the adjustments related to unrealized investment gains and losses previously included in the reserves balance prior to the adoption of ASU 2018-12.
3Adjustment for loss contracts represents the adjustment for those cohorts whose net premium ratio exceeded 100 percent as of the transition date. For those cohorts, the net premiums were set equal to the gross premiums and the difference was recorded as a transition adjustment to the liability for future policy benefits.
4This amount reflects the effect of the reclassification of certain unearned premium. This amount was reclassified to more closely align with the presentation of liabilities under ASU 2018-12 and had no impact to stockholders' equity.
5These amounts represent the portion of reinsurance recoverable related to the liability for future policy benefits. These amounts include the adjustments for the removal of shadow adjustments and for the effect of change in discount rate assumptions for the liability for future policy benefits ceded to third party reinsurers.

	Unum US Segment
	Group Disability		Group Life and AD&D		Individual Disability		Voluntary Disability		Dental and Vision		Total
	(in millions of dollars)
Balance at December 31, 2020	$	7,409.0	$	1,123.9	$	2,485.3	$	1,154.9	$	11.5	$	12,184.6
Removal of Shadow Adjustments	(1,025.2)		(88.5)		(446.1)		(9.9)		—		(1,569.7)
Effect of Change in Discount Rate Assumptions	911.9		91.9		728.5		519.5		—		2,251.8
Other	—		—		—		(5.3)		—		(5.3)
Balance at January 1, 2021	7,295.7		1,127.3		2,767.7		1,659.2		11.5		12,861.4
Reinsurance Recoverable	58.3		3.0		260.6		35.7		0.1		357.7
Balance, Net of Reinsurance, at January 1, 2021	$	7,237.4	$	1,124.3	$	2,507.1	$	1,623.5	$	11.4	$	12,503.7

	Closed Block Segment
	Long-term Care		All Other		Total
	(in millions of dollars)
Balance at December 31, 2020	$	16,283.4	$	12,289.4	$	28,572.8
Removal of Shadow Adjustments	(3,465.4)		(600.2)		(4,065.6)
Effect of Change in Discount Rate Assumptions	9,922.9		2,561.9		12,484.8
Balance at January 1, 2021	22,740.9		14,251.1		36,992.0
Reinsurance Recoverable	44.4		9,957.0		10,001.4
Balance, Net of Reinsurance, at January 1, 2021	$	22,696.5	$	4,294.1	$	26,990.6

Deferred Acquisition Costs (DAC)

The following tables summarize the changes in DAC due to the adoption of ASU 2018-12 and the resulting adjusted balance at January 1, 2021. The removal of shadow adjustments is recorded as a transition adjustment to AOCI.

	Consolidated
	Unum US1		Unum International		Colonial Life		Total
	(in millions of dollars)
Balance at December 31, 2020	$	1,168.7	$	32.0	$	1,071.9	$	2,272.6
Removal of Shadow Adjustments	12.3		—		72.8		85.1
Balance at January 1, 2021	$	1,181.0	$	32.0	$	1,144.7	$	2,357.7
1The $12.3 million removal of shadow adjustments is related to the Unum US voluntary benefits product line.

The following tables present the effect of the adoption of ASU 2018-12 on our historical consolidated financial statements:

	December 31, 2022
	Historical Accounting Method		As Adjusted		Effect of Change
	(in millions of dollars)
Consolidated Balance Sheets
Assets
Reinsurance Recoverable	$	10,218.6	$	9,608.0	$	(610.6)
Deferred Acquisition Costs	2,252.3		2,560.0		307.7
Deferred Income Tax	449.8		586.0		136.2
Other Assets1	1,786.3		1,666.6		(119.7)
Total Assets	61,434.9		61,148.5		(286.4)
Liabilities
Policy and Contract Benefits2	$	1,839.8	$	—	$	(1,839.8)
Reserves for Future Policy and Contract Benefits2	42,330.2		—		(42,330.2)
Future Policy Benefits2	—		38,577.1		38,577.1
Policyholders' Account Balances2	—		5,740.2		5,740.2
Unearned Premiums	352.7		365.5		12.8
Deferred Income Tax	9.2		25.2		16.0
Total Liabilities	52,237.4		52,413.5		176.1
Stockholders' Equity
Accumulated Other Comprehensive Loss	$	(2,756.6)	$	(3,448.3)	$	(691.7)
Retained Earnings	12,912.1		13,141.3		229.2
Total Stockholders' Equity	9,197.5		8,735.0		(462.5)
1The change in other assets is driven by the cost of reinsurance associated with the second phase of our Closed Block individual disability reinsurance transaction which was completed in the first quarter of 2021. In accordance with the provisions of the ASU related to non-contemporaneous reinsurance, we were then required to establish the ceded reserves using an upper-medium grade fixed-income instrument as of the reinsurance transaction date in March 2021 which resulted in higher ceded reserves compared to that which was reported historically.
2We previously reported policy and contract benefits and reserves for future policy and contract benefits liabilities in our consolidated balance sheet as of December 31, 2022 of $1,839.8 million and $42,330.2 million, respectively, resulting in total policyholder liabilities of $44,170.0 million. These balances were reclassified into new line items, future policy benefits and policyholders' account balances, which would have reported balances of $38,443.2 million and $5,726.8 million, respectively, as of December 31, 2022, resulting in total policyholder liabilities of $44,170.0 million under the historical accounting method.

	Twelve Months Ended December 31, 2022
	Historical Accounting Method		As Adjusted		Effect of Change
	(in millions of dollars, except share data and where noted)
Consolidated Statements of Income
Premium Income	$	9,623.4	$	9,616.5	$	(6.9)
Policy Benefits1	6,936.7		7,542.1		605.4
Policy Benefits - Remeasurement Gain	—		(547.5)		(547.5)
Amortization of Deferred Acquisition Costs	591.0		421.1		(169.9)
Other Expenses	1,020.2		1,006.7		(13.5)
Income Tax - Deferred	(156.3)		(130.7)		25.6
Net Income	1,314.2		1,407.2		93.0
Net Income Per Common Share
Basic	$	6.55	$	7.01	$	0.46
Assuming Dilution	$	6.50	$	6.96	$	0.46
Consolidated Statements of Comprehensive Income (Loss)
Net Income	$	1,314.2	$	1,407.2	$	93.0
Change in Adjustment to Deferred Acquisition Costs and Reserves for Future Policy and Contract Benefits, Net of Reinsurance	4,056.9		—		(4,056.9)
Change in the Effect of Discount Rate Assumptions on the Liability for Future Policy Benefits, Net of Reinsurance	—		8,884.6		8,884.6
Change in Foreign Currency Translation Adjustment	(115.2)		(116.0)		(0.8)
Comprehensive Income (Loss)	(1,796.5)		3,123.5		4,920.0
Consolidated Statements of Stockholders' Equity
Accumulated Other Comprehensive Income (Loss)
Balance at Beginning of Year	$	354.1	$	(5,164.6)	$	(5,518.7)
Other Comprehensive Income (Loss)	(3,110.7)		1,716.3		4,827.0
Retained Earnings
Balance at Beginning of Year	11,853.2		11,989.4		136.2
Net Income	1,314.2		1,407.2		93.0
Consolidated Statements of Cash Flows
Cash Flows from Operating Activities
Net Income	$	1,314.2	$	1,407.2	$	93.0
Change in Receivables	566.0		590.6		24.6
Change in Deferred Acquisition Costs	34.1		(135.8)		(169.9)
Change in Insurance Liabilities	(282.0)		(244.7)		37.3
Change in Income Taxes	(58.8)		(31.3)		27.5
Amortization of the Cost of Reinsurance	63.8		50.3		(13.5)
Other, Net	16.1		17.1		1.0
1 Previously disclosed as Benefits and Change in Reserves for Future Benefits

	Twelve Months Ended December 31, 2021
	Historical Accounting Method		As Adjusted		Effect of Change
	(in millions of dollars, except share data and where noted)
Consolidated Statements of Income
Premium Income	$	9,481.0	$	9,475.0	$	(6.0)
Policy Benefits1	7,598.6		8,113.3		514.7
Policy Benefits - Remeasurement Gain	—		(559.9)		(559.9)
Deferral of Acquisition Costs	(508.1)		(523.2)		(15.1)
Amortization of Deferred Acquisition Costs	586.1		452.1		(134.0)
Other Expenses	1,008.6		999.3		(9.3)
Income Tax - Deferred	26.0		66.8		40.8
Net Income	824.2		981.0		156.8
Net Income Per Common Share
Basic	$	4.04	$	4.80	$	0.76
Assuming Dilution	$	4.02	$	4.79	$	0.77
Consolidated Statements of Comprehensive Income (Loss)
Net Income	$	824.2	$	981.0	$	156.8
Change in Adjustment to Deferred Acquisition Costs and Reserves for Future Policy and Contract Benefits, Net of Reinsurance	1,195.9		—		(1,195.9)
Change in the Effect of Discount Rate Assumptions on the Liability for Future Policy Benefits, Net of Reinsurance	—		2,361.8		2,361.8
Change in Foreign Currency Translation Adjustment	(12.6)		(12.8)		(0.2)
Comprehensive Income (Loss)	804.1		2,126.6		1,322.5
Consolidated Statements of Stockholders' Equity
Accumulated Other Comprehensive Income (Loss)
Balance at Beginning of Year	$	374.2	$	(6,310.2)	$	(6,684.4)
Other Comprehensive Income (Loss)	(20.1)		1,145.6		1,165.7
Retained Earnings
Balance at Beginning of Year	11,269.6		11,249.0		(20.6)
Net Income	824.2		981.0		156.8
Consolidated Statements of Cash Flows
Cash Flows from Operating Activities
Net Income	$	824.2	$	981.0	$	156.8
Change in Receivables	678.0		676.1		(1.9)
Change in Deferred Acquisition Costs	78.0		(71.1)		(149.1)
Change in Insurance Liabilities	74.2		37.7		(36.5)
Change in Income Taxes	295.3		335.3		40.0
Amortization of the Cost of Reinsurance	79.1		69.8		(9.3)
1 Previously disclosed as Benefits and Change in Reserves for Future Benefits