Business segment information (Details 2) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Business Segment Information Details 2
United States, Amount	$ 21,271	$ 25,203	$ 23,804
United States, Percent	73.00%	81.00%	78.00%
Germany, Amount	$ 6,210	$ 4,688	$ 5,121
Germany, Percent	22.00%	15.00%	17.00%
Total Amount	$ 27,481	$ 29,861	$ 28,925

No definition available.

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- Definition

Net export sales percentage, US.

+ References

No definition available.

+ Details

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- Definition

Net export sales percentage, Germany.

+ References

No definition available.

+ Details

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- Definition

Reflects the net positive or negative amount derived from subtracting from net proceeds of sale, the carrying amounts, net of allocated reserves, of accounts receivable transferred to a third party in a transaction that qualifies for sales treatment.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 860

-SubTopic 20

-Section 50

-Paragraph 5

-URI http://asc.fasb.org/extlink&oid=51814546&loc=d3e107425-111719

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- Definition

Reflects the net positive or negative amount derived from subtracting from net proceeds of sale the carrying amounts, net of allocated reserves, of notes receivable transferred to a third party in a transaction that qualifies for sales treatment.

+ References

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- Definition

The increase (decrease) during the reporting period in the total amount due within one year (or one operating cycle) from all parties, associated with underlying transactions that are classified as operating activities.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3602-108585

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