Common shares owned accounted for as available for sale securities.

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Represents the historical cost during the period

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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.

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Fair value portion of investments in an entity not consolidated. Includes, but is not limited to, investments in an entity that is affiliated with the reporting entity by means of direct or indirect ownership, an entity in which the reporting entity shares control of the entity with another party or group, an entity which the company has significant influence, but does not have control and subsidiaries that are not required to be consolidated and are accounted for using the equity or cost method.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 1
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- Definition

The net change in the difference between the fair value and the carrying value, or in the comparative fair values, of investments, not including unrealized gains or losses on securities separately or otherwise categorized as trading, available-for-sale, or held-to-maturity, held at each balance sheet date and included in earnings for the period.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
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Fair Value of Assets and Liabilities - Recurring and Nonrecurring Assets (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Fair Value of Assets and Liabilities
Common shares owned in RMR Inc. (in shares)	1,214,225		1,214,225
Historical cost	$ 26,888		$ 26,888
Unrealized gain on equity securities	17,425	$ 0	40,677	$ 0
Recurring
Fair Value of Assets and Liabilities
Investment in RMR Inc.	112,680		112,680
Recurring \| Level 1 inputs
Fair Value of Assets and Liabilities
Investment in RMR Inc.	112,680		112,680
Recurring \| Level 2 inputs
Fair Value of Assets and Liabilities
Investment in RMR Inc.	0		0
Recurring \| Level 3 inputs
Fair Value of Assets and Liabilities
Investment in RMR Inc.	$ 0		$ 0