Acquisitions of Rental Property - Acquisitions of Rental Property Closed (Parenthetical) - (Detail) $ in Thousands	Sep. 30, 2021 USD ($)
Business Combinations [Abstract]
Acquisition costs capitalized	$ 4,432

Amount of deferred policy acquisition cost capitalized on contract remaining in force.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 30
-Section 50
-Paragraph 2B
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=124505477&loc=SL117422543-158416

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 30
-Section 50
-Paragraph 2B
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=124505477&loc=SL117422543-158416

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 825
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=124506110&loc=d3e32546-158582

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 40
-Section 65
-Paragraph 2
-Subparagraph (g)(1)
-URI http://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(7))
-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

Reference 6: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 30
-Section 55
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=124504731&loc=d3e11522-158419

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