Other	3 Months Ended
Other	Mar. 31, 2021
Other Disclosures [Abstract]
Reinsurance	Reinsurance In December 2020, we completed the first phase of a reinsurance transaction, pursuant to which Provident Life and Accident Insurance Company, The Paul Revere Life Insurance Company, and Unum Life Insurance Company of America, wholly-owned domestic insurance subsidiaries of Unum Group, and collectively referred to as "the ceding companies", each entered into separate reinsurance agreements with Commonwealth Annuity and Life Insurance Company (Commonwealth), to reinsure on a coinsurance basis effective as of July 1, 2020, approximately 75 percent of the Closed Block individual disability business, primarily direct business written by the ceding companies. On March 31, 2021, we completed the second phase of the reinsurance transaction, pursuant to which the ceding companies and Commonwealth amended and restated their respective reinsurance agreements to reinsure on a coinsurance and modified coinsurance basis effective as of January 1, 2021, a substantial portion of the remaining Closed Block individual disability business that was not ceded in December 2020, primarily business previously assumed by the ceding companies. Commonwealth established and will maintain collateralized trust accounts for the benefit of the ceding companies to secure its obligations under the reinsurance agreements. In December 2020, Provident Life and Casualty Insurance Company (PLC), also a wholly-owned domestic insurance subsidiary of Unum Group, entered into an agreement with Commonwealth whereby PLC will provide a 12-year volatility cover to Commonwealth for the active life cohort (ALR cohort). On March 31, 2021, PLC and Commonwealth amended and restated this agreement to incorporate the ALR cohort related to the additional business that was reinsured between the ceding companies and Commonwealth as part of the second phase of the transaction. As part of the amended and restated volatility cover, PLC received a payment from Commonwealth of approximately $18 million. At the end of the 12-year coverage period, Commonwealth will retain the remaining incidence and claims risk on the ALR cohort of the ceded business. In connection with the second phase of the reinsurance transaction, Commonwealth paid a total ceding commission to the ceding companies of $18.2 million. The ceding companies transferred assets of $767.0 million, which consisted primarily of cash and fixed maturity securities. In addition, we recognized the following in the first quarter of 2021 related to the second phase: •Net realized investment gains totaling $67.6 million related to the transfer of investments. •Increase in benefits and change in reserves for future benefits of $133.1 million resulting from the realization of previously unrealized investment gains and losses recorded in accumulated other comprehensive income. •Transaction costs totaling $6.2 million. •Reinsurance recoverable of $990.0 million related to the policies on claim status. •Payable of $307.2 million related to the portfolio of invested assets associated with the business ceded on a modified coinsurance basis. •Cost of reinsurance, or prepaid reinsurance premium, of $43.1 million related to the DLR cohort. The total cost of reinsurance recognized on a combined basis for the first and second phases was $854.8 million for which we amortized $20.0 million during the first three months of 2021. •Deposit asset of $5.0 million related to the ALR cohort. The total deposit asset recognized on a combined basis for the first and second phases was $91.8 million.
Allowance for Expected Credit Losses on Premiums Receivable	Allowance for Expected Credit Losses on Premiums Receivable At March 31, 2021 and December 31, 2020, the allowance for expected credit losses on premiums receivables was $33.7 million and $38.8 million, respectively, on gross premiums receivables of $602.9 million and $525.8 million, respectively. The decrease in the allowance of $5.1 million during the three months ended March 31, 2021 was driven primarily by improvements in the age of premiums due to be collected and improvements in unemployment levels. At March 31, 2020 and January 1, 2020, the allowance for expected credit losses on premiums receivables was $32.6 million and $23.8 million, respectively, on gross premiums receivables of $607.2 million and $543.0 million, respectively. The increase in the allowance of $8.8 million during the first quarter of 2020 was driven primarily by the increase in unemployment levels and the general uncertainty around the financial condition of some of our customers resulting from the impacts of COVID-19.