Employee Retirement plans (Details)	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Average increase of salaries	3.00%	3.00%	3.00%
Discounted interest rate	3.00%	4.50%	4.75%
Turn over	actuarial standard and average of the last 5 years	actuarial standard and average of the last 5 years	actuarial standard and average of the last 5 years
Age of retirement	60 to 65 years actuarial standard based on age and professional status	60 to 65 years actuarial standard based on age and professional status	60 to 65 years actuarial standard based on age and professional status

The interest rate used to adjust for the time value of money for the plan.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 132R

-Paragraph 5

-Subparagraph j

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (k)(1)

-URI http://asc.fasb.org/extlink&oid=21915506&loc=d3e1928-114920

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