Redeemable Noncontrolling Interests (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Beginning balance	$ 12,244
Sale of a subsidiary with redeemable noncontrolling interests	4,144	$ 4,395	$ 2,479
Exercises of redeemable noncontrolling interests	1,695	2,541	966
Ending balance	11,882	12,244
Payments to Acquire Additional Interest in Subsidiaries	13,900
Redeemable Noncontrolling Interest [Member]
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Beginning balance	99,043	81,806
Acquired through acquisitions		23,594
Sale of a subsidiary with redeemable noncontrolling interests	2,814	666
Redemption value adjustment for the current period	(1,803)	2,097
Exercises of redeemable noncontrolling interests	(11,923)	(13,632)
Exercises of redeemable noncontrolling interests	(2,017)	(753)
Impact of foreign exchange translation	12,864	(126)
Measurement period adjustments	(1,426)	5,391
Ending balance	$ 97,552	$ 99,043	$ 81,806

Noncontrolling Interest, Impact Of Foreign Exchange Translation

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Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which is directly or indirectly attributable to that ownership interest in subsidiary equity which is not attributable to the parent (that is, noncontrolling interest, previously referred to as minority interest).

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Change in noncontrolling interest during the period as a result of a change in the redemption value of redeemable noncontrolling interest.

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Decrease in noncontrolling interest balance from payment of dividends or other distributions by the non-wholly owned subsidiary or partially owned entity, included in the consolidation of the parent entity, to the noncontrolling interest holders.

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Decrease in noncontrolling interest (for example, but not limited to, redeeming or purchasing the interests of noncontrolling shareholders, issuance of shares (interests) by the non-wholly owned subsidiary to the parent entity for other than cash, and a buyback of shares (interest) by the non-wholly owned subsidiary from the noncontrolling interests).

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Net Increase or Decrease in balance of noncontrolling interest in the subsidiary during the reporting period.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Amount of Net Income (Loss) attributable to noncontrolling interest.

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Amount of increase in noncontrolling interest from a business combination.

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The cash outflow associated with the purchase of noncontrolling interest during the period.

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