Other operating (income) / expenses (Details) - USD ($)	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Other operating (income) / expenses [Abstract]
Provision made for damages to be recognized as claims when recovery can be assured	$ 315,498
Voluntary special contribution	$ 195,499
Insurance recoveries		$ 522,781

The amount of the provision for expected and allowed claims included in liabilities subject to compromise.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 852
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6918054&loc=d3e56015-112765

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 852
-SubTopic 10
-Section 45
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=49172455&loc=d3e55717-112764

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 852
-SubTopic 10
-Section 55
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=34712771&loc=d3e56145-112766

Name:	us-gaap_LiabilitiesSubjectToCompromiseProvisionForExpectedAndAllowedClaims
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant