Commitments and Contingencies - Additional Information (Detail) - Hotel Development Projects - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2020	Mar. 31, 2021
Commitments and Contingencies Disclosure [Line Items]
Investment in other invested assets	$ 0.8
Maximum
Commitments and Contingencies Disclosure [Line Items]
Guaranteed debt of entities		$ 5.3

Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=121555522&loc=d3e12069-110248

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