Fair Value Measurements (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Fair Value Measurements
Transfer of assets and liabilities between fair value hierarchy	$ 0	$ 0	$ 0	$ 0

Amount of transfers of assets and liabilities measured on a recurring basis of the fair value hierarchy into Level 1.

No definition available.

Name:	avgr_FairValueAssetsLiabilitiesTransfersAmount
Namespace Prefix:	avgr_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration