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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Percentage points added to the reference rate to compute the variable rate on the debt instrument.

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Incremental percentage increase (decrease) in the stated rate on a debt instrument.

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Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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- Definition

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=98513485&loc=d3e4304-108586

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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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- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(b),22(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

The cash outflow to settle a bank borrowing during the year.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (b)
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- Definition

Describes the event or transaction that occurred between the balance sheet date and the date the financial statements are issued or available to be issued.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 855
-SubTopic 10
-Section 50
-Paragraph 2
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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 (Details) - USD ($)						1 Months Ended	6 Months Ended
	Sep. 27, 2017	Sep. 13, 2017	Aug. 04, 2017	Jul. 26, 2017	Apr. 30, 2015	Apr. 30, 2017	Jun. 30, 2017	Jun. 30, 2016	Aug. 08, 2017	Aug. 07, 2017	Feb. 28, 2017
Subsequent Event [Line Items]
Repayment of bank term loans							$ 5,625,000	$ 11,250,000
Subsequent Event
Subsequent Event [Line Items]
Dividends declared per common share (usd per share)				$ 0.45
Dividend payable date	Sep. 27, 2017
Dividend record date		Sep. 13, 2017
Subsequent event, description				The Board of Directors of the Company declared a quarterly dividend
Cogent 36 Month Facility
Subsequent Event [Line Items]
Debt instrument term (years)					3 years
Repayment of bank term loans						$ 5,600,000
Cogent 36 Month Facility \| Subsequent Event
Subsequent Event [Line Items]
Debt instrument term (years)			3 years
Repayment of bank term loans			$ 5,600,000
Weighted average interest rate (percent)			0.50%
Basis spread on variable rate (percent)			0.75%
Revolving Credit Facility
Subsequent Event [Line Items]
Revolving loan facility, maximum borrowing capacity							$ 80,000,000				$ 70,000,000
Revolving Credit Facility \| Subsequent Event
Subsequent Event [Line Items]
Revolving loan facility, maximum borrowing capacity									$ 90,000,000.0	$ 80,000,000.0