Aggregate dividends paid during the period for each share of common stock outstanding.

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Aggregate dividends declared during the period for each share of common stock outstanding.

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Amount of cash outflow in the form of ordinary dividends to common shareholders of the parent entity.

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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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The number of shares purchased on the open market during the period for issuance to employees under the plan.

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Shareholders' Equity (Details) - USD ($) $ / shares in Units, $ in Thousands				3 Months Ended
	Apr. 18, 2019	Apr. 05, 2019	Feb. 21, 2019	Mar. 31, 2019	Mar. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividends paid (in dollars per share)			$ 0.39
Distributions to shareholders			$ 92,714	$ 92,714	$ 92,674
Subsequent Event
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Distributions to common shareholders declared (in dollars per share)	$ 0.15
Distributions to shareholders	$ 35,659
Subsequent Event \| Former Employees Of RMR LLC
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares purchased to satisfy tax withholding and payment obligations (in shares)		3,529
Distributions to common shareholders declared (in dollars per share)		$ 9.47