Subsequent event and dividends (Details Textual) (USD $) In Thousands, except Per Share data, unless otherwise specified	1 Months Ended
Jul. 27, 2012	Jul. 29, 2012 Subsequent Event [Member]
Loss Contingencies [Line Items]
Amount received for settlement of certain legal proceedings and grant of permanent easement		$ 2,650
Dividends (Textual) [Abstract]
Dividend Declared	$ 0.04
Dividend payable, declared	Jul. 25, 2012
Outstanding common stock payable date	Aug. 08, 2012
Dividends Payable Date on record	Aug. 22, 2012

Amount received for settlement of certain legal proceedings and grant of permanent easement.

No definition available.

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- Details

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- Definition

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

+ References

+ Details

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- Definition

The per share amount of a dividend declared, but not paid, as of the financial reporting date.

+ 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

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 32

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

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- Definition

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

+ References

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- Definition

Date the holder must own the stock to be entitled to the dividend, in CCYY-MM-DD format.

+ References

No definition available.

+ Details

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