Date the declared dividend will be paid, in CCYY-MM-DD format.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4304-108586

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- Definition

Date the dividend to be paid was declared, in CCYY-MM-DD format.

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- Definition

Date the holder must own the stock to be entitled to the dividend, in CCYY-MM-DD format.

+ References

No definition available.

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- Definition

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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- Definition

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

+ References

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Shareholders' Equity - Summary of Preferred Stock Dividends and Distributions (Detail) - $ / shares				1 Months Ended	6 Months Ended
	Jul. 24, 2018	Apr. 24, 2018	Feb. 20, 2018	Dec. 31, 2017	Jun. 30, 2018
Dividends Payable [Line Items]
Series A Preferred Share					$ 0.8750
Series A Preferred Shares [Member]
Dividends Payable [Line Items]
Declaration Date		Apr. 24, 2018	Feb. 20, 2018	Feb. 20, 2018
Record Date		Jun. 29, 2018	Mar. 30, 2018	Mar. 30, 2018
Payment Date		Jul. 16, 2018	Apr. 16, 2018	Apr. 16, 2018
Series A Preferred Share		$ 0.43750	$ 0.43750	$ 0.15556
Subsequent Event [Member] \| Series A Preferred Shares [Member]
Dividends Payable [Line Items]
Declaration Date	Jul. 24, 2018
Record Date	Sep. 28, 2018
Payment Date	Oct. 15, 2018
Series A Preferred Share	$ 0.43750