Summary of significant accounting policies (Details Textual 1) (PMG [Member], Segment, Discontinued Operations [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2010
PMG [Member] \| Segment, Discontinued Operations [Member]
Goodwill [Line Items]
Goodwill Impairment	$ 22.1

Loss recognized during the period that results from the write-down of goodwill after comparing the implied fair value of reporting unit goodwill with the carrying amount of that goodwill. Goodwill is assessed at least annually for impairment.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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-Name Accounting Standards Codification

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

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+ Details