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

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=6367179&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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Date the holder must own the stock to be entitled to the dividend, in CCYY-MM-DD format.

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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.

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Subsequent Events - Additional Information (Detail) - $ / shares			3 Months Ended
	Apr. 19, 2018	Jan. 31, 2018	Mar. 31, 2018	Mar. 31, 2017
Subsequent Event [Line Items]
Dividend declared date		Jan. 31, 2018
Dividend declared		$ 0.250	$ 0.25	$ 0.23
Dividend payable date		Mar. 14, 2018
Closing date of stockholders on record for dividend entitlement		Feb. 28, 2018
Subsequent Event
Subsequent Event [Line Items]
Dividend declared date	Apr. 19, 2018
Dividend declared	$ 0.250
Dividend payable date	May 30, 2018
Closing date of stockholders on record for dividend entitlement	May 16, 2018