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

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-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://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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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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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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Shareholders' Equity - Schedule of Dividends Paid (Detail) - $ / shares	3 Months Ended		12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Dividends Payable [Line Items]
Dividend Per Share	$ 0.35	$ 0.34
Installment One
Dividends Payable [Line Items]
Declaration Date	Feb. 21, 2019		Feb. 21, 2018
Record Date	Mar. 07, 2019		Mar. 07, 2018
Payment Date	Mar. 21, 2019		Mar. 21, 2018
Dividend Per Share	$ 0.35		$ 0.34
Installment Two
Dividends Payable [Line Items]
Declaration Date			Apr. 19, 2018
Record Date			Jun. 06, 2018
Payment Date			Jun. 20, 2018
Dividend Per Share			$ 0.35
Installment Three
Dividends Payable [Line Items]
Declaration Date			Jul. 19, 2018
Record Date			Aug. 22, 2018
Payment Date			Sep. 05, 2018
Dividend Per Share			$ 0.35
Installment Four
Dividends Payable [Line Items]
Declaration Date			Oct. 18, 2018
Record Date			Nov. 21, 2018
Payment Date			Dec. 05, 2018
Dividend Per Share			$ 0.35