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Summary of Restricted Stock Unit Grants Since Inception (Detail) - Restricted Stock Units - shares	12 Months Ended			204 Months Ended	240 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted Stock Awards	0	0	202,905	175,498	378,403
Key Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted Stock Awards	0	0	161,238	175,498	336,736
Directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted Stock Awards	0	0	41,667	0	41,667

X

- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(01)
-URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901

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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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