Segment Reporting - Narrative (Details) $ in Thousands	3 Months Ended
Mar. 31, 2021 USD ($) segment	Mar. 31, 2020 USD ($)
Segment reporting
Number of operating segments \| segment	2
Interest and other income	$ 2,835	$ 138
Operating Segments \| SHOP
Segment reporting
Interest and other income	$ 2,433	$ 0

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.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 18
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8672-108599

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