The numbers of days for which a mortgage loan has been delinquent such that it is considered non-performing.

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- Definition

Amount of financing receivable originated more than five years prior to current fiscal year.

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- Definition

Amount of financing receivable originated four years prior to current fiscal year.

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- Definition

Amount of financing receivable originated in current fiscal year.

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- Definition

Amount of financing receivable originated in fiscal year prior to current fiscal year.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
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-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
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-Section 55
-Paragraph 79
-URI http://asc.fasb.org/extlink&oid=121647567&loc=SL82922352-210448

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- Definition

Amount of financing receivable originated three years prior to current fiscal year.

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- Definition

Amount of financing receivable originated two years prior to current fiscal year.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

Carrying amount as of the balance sheet date of interest earned but not received. Also called accrued interest or accrued interest receivable.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
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- Definition

Amount, before allowance for credit loss, of financing receivable.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 55
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-URI http://asc.fasb.org/extlink&oid=121647567&loc=SL82922352-210448

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- Definition

Amount before valuation allowance recoverable under reinsurance contracts. Examples include, but are not limited to, settled and unsettled claims, incurred but not reported losses, loss adjustment expense, premium paid, policy benefits and policy reserves.

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No definition available.

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Investments - Mortgage Loan Credit Monitoring (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2020	Dec. 31, 2019	Sep. 30, 2019
Financing Receivable, Credit Quality Indicator
Mortgage loans, Total amortized cost	$ 17,562.2	$ 16,513.9	$ 16,520.4
Reinsurance recoverables	1,037.2
Accrued interest receivable	571.9
Commercial mortgage loans
Financing Receivable, Credit Quality Indicator
2020	1,477.1
2019	2,798.5
2018	2,826.3
2017	2,046.6
2016	1,580.8
Prior	4,477.9
Mortgage loans, Total amortized cost	15,207.2	15,017.2	15,018.6
Accrued interest receivable	57.8
Commercial mortgage loans \| A- and above
Financing Receivable, Credit Quality Indicator
2020	1,320.1
2019	2,531.4
2018	2,477.9
2017	1,778.9
2016	1,474.6
Prior	3,882.0
Mortgage loans, Total amortized cost	13,464.9	13,961.9
Commercial mortgage loans \| BBB+ thru BBB-
Financing Receivable, Credit Quality Indicator
2020	106.6
2019	193.4
2018	348.4
2017	262.5
2016	75.0
Prior	516.6
Mortgage loans, Total amortized cost	1,502.5	1,026.9
Commercial mortgage loans \| BB+ thru BB-
Financing Receivable, Credit Quality Indicator
2020	16.2
2019	55.8
2016	25.3
Prior	74.5
Mortgage loans, Total amortized cost	171.8	23.3
Commercial mortgage loans \| B+ and below
Financing Receivable, Credit Quality Indicator
2020	34.2
2019	17.9
2017	5.2
2016	5.9
Prior	4.8
Mortgage loans, Total amortized cost	68.0	5.1
Brick and mortar
Financing Receivable, Credit Quality Indicator
Mortgage loans, Total amortized cost		14,856.7
Brick and mortar \| A- and above
Financing Receivable, Credit Quality Indicator
Mortgage loans, Total amortized cost		13,885.2
Brick and mortar \| BBB+ thru BBB-
Financing Receivable, Credit Quality Indicator
Mortgage loans, Total amortized cost		943.1
Brick and mortar \| BB+ thru BB-
Financing Receivable, Credit Quality Indicator
Mortgage loans, Total amortized cost		23.3
Brick and mortar \| B+ and below
Financing Receivable, Credit Quality Indicator
Mortgage loans, Total amortized cost		5.1
Credit tenant loans
Financing Receivable, Credit Quality Indicator
Mortgage loans, Total amortized cost		160.5
Credit tenant loans \| A- and above
Financing Receivable, Credit Quality Indicator
Mortgage loans, Total amortized cost		76.7
Credit tenant loans \| BBB+ thru BBB-
Financing Receivable, Credit Quality Indicator
Mortgage loans, Total amortized cost		83.8
Direct financing leases
Financing Receivable, Credit Quality Indicator
2020	178.0
2019	26.7
2018	59.0
2017	37.3
2016	17.3
Prior	320.4
Mortgage loans, Total amortized cost	638.7
Accrued interest receivable	0.3
Direct financing leases \| A- and above
Financing Receivable, Credit Quality Indicator
2020	39.4
2019	1.5
2018	38.2
2017	17.2
2016	13.7
Prior	189.4
Mortgage loans, Total amortized cost	299.4
Direct financing leases \| BBB+ thru BBB-
Financing Receivable, Credit Quality Indicator
2020	28.1
2019	5.0
2018	10.1
2017	20.1
2016	2.7
Prior	31.9
Mortgage loans, Total amortized cost	97.9
Direct financing leases \| BB+ thru BB-
Financing Receivable, Credit Quality Indicator
2020	12.0
Prior	1.7
Mortgage loans, Total amortized cost	13.7
Direct financing leases \| B+ and below
Financing Receivable, Credit Quality Indicator
2020	98.5
2019	20.2
2018	10.7
2016	0.9
Prior	97.4
Mortgage loans, Total amortized cost	227.7
Residential mortgage loans
Financing Receivable, Credit Quality Indicator
2020	312.1
2019	404.8
2018	187.3
2017	179.9
2016	203.3
Prior	428.9
Mortgage loans, Total amortized cost	1,716.3	1,496.7	$ 1,501.8
Accrued interest receivable	1.1
Residential mortgage loans \| Performing
Financing Receivable, Credit Quality Indicator
2020	312.1
2019	403.9
2018	186.2
2017	179.9
2016	202.9
Prior	422.1
Mortgage loans, Total amortized cost	1,707.1	1,482.2
Residential mortgage loans \| Non-performing
Financing Receivable, Credit Quality Indicator
2019	0.9
2018	1.1
2016	0.4
Prior	6.8
Mortgage loans, Total amortized cost	$ 9.2	14.5
Mortgage loans, Days delinquent to be considered non-performing	90 days
First liens
Financing Receivable, Credit Quality Indicator
Mortgage loans, Total amortized cost		1,485.7
First liens \| Performing
Financing Receivable, Credit Quality Indicator
Mortgage loans, Total amortized cost		1,474.2
First liens \| Non-performing
Financing Receivable, Credit Quality Indicator
Mortgage loans, Total amortized cost		11.5
Home equity
Financing Receivable, Credit Quality Indicator
Mortgage loans, Total amortized cost		11.0
Home equity \| Performing
Financing Receivable, Credit Quality Indicator
Mortgage loans, Total amortized cost		8.0
Home equity \| Non-performing
Financing Receivable, Credit Quality Indicator
Mortgage loans, Total amortized cost		$ 3.0