XML 49 R35.htm IDEA: XBRL DOCUMENT v2.4.1.9

Property and Equipment, net - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	9 Months Ended		12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Property Plant And Equipment Capitalized Interest Costs [Abstract]
Depreciation expense	$ 10us-gaap_Depreciation	$ 8us-gaap_Depreciation	$ 12us-gaap_Depreciation	$ 11us-gaap_Depreciation	$ 4us-gaap_Depreciation

X

- Definition

The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation.

+ 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 (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

+ Details

Name:	us-gaap_Depreciation
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

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- Details

Name:	zfgn_PropertyPlantAndEquipmentCapitalizedInterestCostsAbstract
Namespace Prefix:	zfgn_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration