Other	6 Months Ended
Jun. 30, 2020
Debt and Other Disclosures [Abstract]
Debt	At June 30, 2020, short-term debt consisted entirely of our 5.625% senior unsecured notes due in the third quarter of 2020. Also included in the carrying amount of short-term debt are deferred debt costs of $0.1 million. During the six months ended June 30, 2020, we made principal payments of $30.0 million on our senior secured non-recourse notes issued by Northwind Holdings, LLC. In May 2020, we issued $500.0 million of 4.500% senior notes due 2025. The notes are callable at or above par and rank equally in the right of payment with all of our other unsecured and unsubordinated debt. At June 30, 2020, letters of credit totaling $0.6 million had been issued from our credit facilities, but there were no borrowed amounts outstanding. Borrowings under the credit facilities are for general corporate uses and are subject to financial covenants, negative covenants, and events of default that are customary. The two primary financial covenants include limitations based on our leverage ratio and consolidated net worth. We are also subject to covenants that limit subsidiary indebtedness. The credit facilities provide for borrowings at an interest rate based either on the prime rate or LIBOR.
Statutory Financial Information	In connection with a financial examination of Unum Life Insurance Company of America (Unum America), which closed at the end of the second quarter of 2020, the Maine Bureau of Insurance (MBOI) concluded that Unum America’s long-term care statutory reserves are deficient by $2.1 billion as of December 31, 2018, the financial statement date of the examination period. The MBOI granted permission to Unum America on May 1, 2020, to phase in the additional statutory reserves over seven years beginning with year-end 2020 and ending with year-end 2026. The 2020 phase-in amount is estimated to be between $200 million and $250 million. This strengthening will be accomplished by our actuaries incorporating explicitly agreed upon margins into our existing assumptions for annual statutory reserve adequacy testing. These actions will add margin to Unum America's best estimate assumptions. Our long-term care reserves and financial results reported under generally accepted accounting principles are not affected by the MBOI’s examination conclusion. We plan to fund the additional statutory reserves with expected cash flows. If the permitted practice was not granted by the MBOI to phase in these additional statutory reserves, the impact to the risk-based capital ratio would have triggered a regulatory event.
Lessee, Operating Leases	During the second quarter of 2020, we recognized an impairment loss of $12.7 million, or $10.0 million after-tax, on the right-of-use (ROU) asset related to one of our operating leases for office space that we do not plan to continue using to support our general operations. The impairment loss was recorded as a result of a decrease in the fair value of the ROU asset compared to its carrying value. The fair value of the ROU asset was determined based on a discounted cash flow model utilizing estimated market rates for sub-lease rentals. The impairment loss is recorded within other expenses in the consolidated statements of income and is included within our Corporate segment.
Subsequent Events	On July 22, 2020, the Finance Bill 2019-21 was enacted, resulting in a U.K. tax rate increase from 17 percent to 19 percent, retroactively effective April 1, 2020, which will result in approximately $9 million of additional tax expense for the revaluation of our tax liabilities in the third quarter of 2020.

Other

6 Months Ended

Jun. 30, 2020

Debt and Other Disclosures [Abstract]

At June 30, 2020, short-term debt consisted entirely of our 5.625% senior unsecured notes due in the third quarter of 2020. Also included in the carrying amount of short-term debt are deferred debt costs of $0.1 million.

During the six months ended June 30, 2020, we made principal payments of $30.0 million on our senior secured non-recourse notes issued by Northwind Holdings, LLC.

In May 2020, we issued $500.0 million of 4.500% senior notes due 2025. The notes are callable at or above par and rank equally in the right of payment with all of our other unsecured and unsubordinated debt.

At June 30, 2020, letters of credit totaling $0.6 million had been issued from our credit facilities, but there were no borrowed amounts outstanding. Borrowings under the credit facilities are for general corporate uses and are subject to financial covenants, negative covenants, and events of default that are customary. The two primary financial covenants include limitations based on our leverage ratio and consolidated net worth. We are also subject to covenants that limit subsidiary indebtedness. The credit facilities provide for borrowings at an interest rate based either on the prime rate or LIBOR.

Statutory Financial Information

In connection with a financial examination of Unum Life Insurance Company of America (Unum America), which closed at the end of the second quarter of 2020, the Maine Bureau of Insurance (MBOI) concluded that Unum America’s long-term care statutory reserves are deficient by $2.1 billion as of December 31, 2018, the financial statement date of the examination period. The MBOI granted permission to Unum America on May 1, 2020, to phase in the additional statutory reserves over seven years beginning with year-end 2020 and ending with year-end 2026. The 2020 phase-in amount is estimated to be between $200 million and $250 million. This strengthening will be accomplished by our actuaries incorporating explicitly agreed upon margins into our existing assumptions for annual statutory reserve adequacy testing. These actions will add margin to Unum America's best estimate assumptions. Our long-term care reserves and financial results reported under generally accepted accounting principles are not affected by the MBOI’s examination conclusion. We plan to fund the additional statutory reserves with expected cash flows. If the permitted practice was not granted by the MBOI to phase in these additional statutory reserves, the impact to the risk-based capital ratio would have triggered a regulatory event.

Lessee, Operating Leases

During the second quarter of 2020, we recognized an impairment loss of $12.7 million, or $10.0 million after-tax, on the right-of-use (ROU) asset related to one of our operating leases for office space that we do not plan to continue using to support our general operations. The impairment loss was recorded as a result of a decrease in the fair value of the ROU asset compared to its carrying value. The fair value of the ROU asset was determined based on a discounted cash flow model utilizing estimated market rates for sub-lease rentals. The impairment loss is recorded within other expenses in the consolidated statements of income and is included within our Corporate segment.

Subsequent Events

On July 22, 2020, the Finance Bill 2019-21 was enacted, resulting in a U.K. tax rate increase from 17 percent to 19 percent, retroactively effective April 1, 2020, which will result in approximately $9 million of additional tax expense for the revaluation of our tax liabilities in the third quarter of 2020.