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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Carrying value as of the balance sheet date of dividends declared but unpaid on equity securities issued by the entity and outstanding.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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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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Shareholder's Equity - Distribution to Common Shareholders (Details) - USD ($) $ / shares in Units, $ in Thousands					3 Months Ended
	May 17, 2018	Apr. 19, 2018	Feb. 22, 2018	Jan. 19, 2018	Mar. 31, 2018	Mar. 31, 2017
Subsequent Event [Line Items]
Distribution to common shareholders (in dollars per share)			$ 0.39
Distribution to common shareholders			$ 92,674		$ 92,674	$ 92,642
Distributions to common shareholders declared (in dollars per share)				$ 0.39
Distribution payable				$ 92,674
Subsequent Event
Subsequent Event [Line Items]
Distributions to common shareholders declared (in dollars per share)		$ 0.39
Distribution payable		$ 92,675
Scenario, Forecast
Subsequent Event [Line Items]
Distribution to common shareholders (in dollars per share)	$ 0.39
Distribution to common shareholders	$ 92,675