Summary of significant accounting policies.

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Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 4
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-Name Accounting Standards Codification
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-Publisher FASB
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-Topic 210
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-Section S99
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A savings certificate entitling the Entity (that is, bearer) to receive interest at an established maturity date, based upon a fixed interest rate. A certificate of deposit may be issued in any denomination. Certificates of deposit are generally issued by commercial banks and, therefore, insured by the FDIC (up to the prescribed limit). Certificates of deposit generally restrict holders from withdrawing funds on demand without the incurrence of penalties. Generally, only certificates of deposit with original maturities of three months or less qualify as cash equivalents. Original maturity means original maturity to the entity holding the investment. As a related example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three-years ago does not become a cash equivalent when its remaining maturity is three months.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(1))
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Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

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Amount of gain (loss) from sale and disposal of integrated set of activities and assets capable of being conducted and managed for purpose of providing return in form of dividend, lower cost, or other economic benefit to investor, owner, member and participant.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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-Topic 230
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-Section 50
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Term of lessee's operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 3
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Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues.

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-Topic 280
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-Section 50
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Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

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The cash inflow associated with the amount received from the sale of a portion of the company's business, for example a segment, division, branch or other business, during the period.

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Summary of Significant Accounting Policies - Additional Information (Details) $ in Thousands	1 Months Ended			12 Months Ended
	Dec. 31, 2020 USD ($)	Oct. 31, 2020 USD ($)	Aug. 31, 2020 USD ($)	Dec. 31, 2022 USD ($) Segment	Dec. 31, 2021 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Certificates Of Deposit				$ 8,200	$ 9,800
Cash and cash equivalents				$ 497,070	$ 1,040,039
Lessee, Operating Lease, Term of Contract				12 months
Number of Operating Segments \| Segment				1
Number of Reportable Segments \| Segment				1
Southern California Operations
Summary Of Significant Accounting Policies [Line Items]
Proceeds from Divestiture of Businesses	$ 1,000	$ 26,000	$ 2,500
Gain (Loss) on Disposition of Business		$ 19,100	$ 1,300
Minimum
Summary Of Significant Accounting Policies [Line Items]
Finite-Lived Intangible Asset, Useful Life				2 years
Maximum
Summary Of Significant Accounting Policies [Line Items]
Finite-Lived Intangible Asset, Useful Life				30 years