Commercial Mortgage Loans - Narrative (Details) - Commercial mortgage loans $ in Millions	Dec. 31, 2021 USD ($) loan	Dec. 31, 2020 USD ($) loan
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of mortgage loans in foreclosure \| loan	1	1
Recorded investment in mortgage loans 90 or more days past due	$ 0.6	$ 0.6
Unpaid principal balance of loans in foreclosure	$ 0.6	$ 0.8

This item represents the aggregate fair value of loans held as assets that are 90 days or more past due for which the fair value option has been elected.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 28
-Subparagraph (e)(1)
-URI http://asc.fasb.org/extlink&oid=123596393&loc=d3e14064-108612

Name:	us-gaap_FairValueOptionLoansHeldAsAssets90DaysOrMorePastDue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant