Subsequent Events - Additional Information (Detail) - Subsequent Event [Member]	Sep. 21, 2018 $ / shares
Subsequent Event [Line Items]
Dividend payable date	Nov. 05, 2018
Dividend payable, date of record	Oct. 12, 2018
Common Stock [Member]
Subsequent Event [Line Items]
Dividend payable per share	$ 0.225

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

The per share amount of a dividend declared, but not paid, as of the financial reporting date.

+ References

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- Definition

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

+ References

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- Definition

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

+ References

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