Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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-Topic 326
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-Section 45
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Balance Type:	debit
Period Type:	instant

- Definition

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)(1)
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-Publisher FASB
-Name Accounting Standards Codification
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-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
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-Name Accounting Standards Codification
-Topic 210
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-Section S99
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-Name Accounting Standards Codification
-Topic 942
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-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

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Balance Type:	credit
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1B
-Subparagraph (b)
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Period Type:	instant

- Definition

The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The cash inflow from additional borrowings, net of cash paid to third parties in connection with debt origination.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (b)
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Period Type:	duration

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- Details

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Schedule 2 - Parent Company Financial Statements - Balance Sheets (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Sep. 22, 2020	Jun. 07, 2019
Amortized cost of fixed maturities	$ 7,358.2	$ 6,692.7
Long-term Debt, Current and Non-current	$ 1,152.1	1,247.8
Senior Notes \| Senior Notes Payable, 4.35% due 2025 (Fair Value: 2021 – $481.4; 2020 – $499.5)
Stated interest rate, percentage	4.35%
Long-term debt, gross	$ 450.0
Senior Notes \| Senior Notes, 2.400 Percent Due September 30, 2030
Stated interest rate, percentage			2.40%
Long-term debt, gross	400.0
Proceeds from debt, net of issuance costs	395.8
Subordinated Debt \| Subordinated Debentures due 2054 (Fair Value: 2018 – $151.1)
Stated interest rate, percentage				7.375%
Long-term debt, gross				$ 150.0
Parent Company
Amortized cost of fixed maturities	0.3	91.8
Parent Company \| Secured Debt \| Term Loan due July 5, 2023 (Fair Value: 2021 – $—; 2020 – $50.0)
Long-term Debt, Current and Non-current	0.0	50.0
Parent Company \| Senior Notes \| Senior Notes Payable, 4.35% due 2025 (Fair Value: 2021 – $481.4; 2020 – $499.5)
Long-term Debt, Current and Non-current	481.4	499.5
Parent Company \| Senior Notes \| Senior Notes, 2.400 Percent Due September 30, 2030
Long-term Debt, Current and Non-current	$ 387.8	$ 405.6