Schedule of Dividends Declared (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Sep. 30, 2018	Sep. 30, 2017
Class of Stock
Dividends declared per share (in usd per share)	$ 0.06	$ 0.06	$ 0.06	$ 0.06	$ 0.06	$ 0.06	$ 0.18	$ 0.18
Aggregate amount of dividends	$ 2,569	$ 2,565	$ 2,565	$ 2,564	$ 2,561	$ 1,301	$ 7,699	$ 6,426

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- Definition

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

+ References

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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- Definition

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

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