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Noncontrolling and Redeemable Noncontrolling Interests (Details Textual) - USD ($) $ in Thousands | Sep. 30, 2021 | Dec. 31, 2020 | Dec. 31, 2019
--- | --- | --- | ---
Noncontrolling Interest [Line Items] |  |  |
Redeemable Noncontrolling Interest, Equity, Fair Value | $ 29,787 | $ 604 | $ 3,603
Vesting over period [Member] |  |  |
Noncontrolling Interest [Line Items] |  |  |
Redeemable Noncontrolling Interest, Equity, Fair Value | 14,847 |  |
Termination, disability, or death [Member] |  |  |
Noncontrolling Interest [Line Items] |  |  |
Redeemable Noncontrolling Interest, Equity, Fair Value | 14,940 |  |
Acquisition Value in excess of Redemption Value [Member] |  |  |
Noncontrolling Interest [Line Items] |  |  |
Redeemable Noncontrolling Interest, Equity, Fair Value | $ 0 |  |

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- Definition The aggregate fair value as of the reporting date of all noncontrolling interests which are redeemable by the (parent) entity (1) at a fixed or determinable price on a fixed or determinable date, (2) at the option of the holder of the noncontrolling interest, or (3) upon occurrence of an event that is not solely within the control of the (parent) entity. This item includes noncontrolling interest holder's ownership (or holders' ownership) regardless of the type of equity interest (common, preferred, other) including all potential organizational (legal) forms of the investee entity. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 480 -SubTopic 10 -Section S99 -Paragraph 3A -Subparagraph 14 -URI http://asc.fasb.org/extlink&oid=65877616&loc=SL6540498-122764 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 480 -SubTopic 10 -Section S99 -Paragraph 3A -Subparagraph (16)(c) -URI http://asc.fasb.org/extlink&oid=65877616&loc=SL6540498-122764 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 480 -SubTopic 10 -Section S99 -Paragraph 3A -Subparagraph (12)(c) -URI http://asc.fasb.org/extlink&oid=65877616&loc=SL6540498-122764 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 480 -SubTopic 10 -Section S99 -Paragraph 3A -Subparagraph 15 -URI http://asc.fasb.org/extlink&oid=65877616&loc=SL6540498-122764 + Details
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