Stockholders' Equity - Additional Information (Detail) - USD ($)	3 Months Ended
Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015
Equity [Abstract]
Dividends declared, per share	$ 0.17	$ 0.14	$ 0.14	$ 0.14	$ 0.14
Dividends paid, per share	$ 0.17	$ 0.14	$ 0.14	$ 0.14	$ 0.14
Dividend payments, amount	$ 1,936,421				$ 1,582,000

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

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Amount of paid and unpaid common stock dividends declared with the form of settlement in cash.

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