CONSOLIDATED STATEMENTS OF STOCKHOLDERS' DEFICIT (Parenthetical) $ in Millions	12 Months Ended
Dec. 31, 2017 USD ($)
Statement Of Stockholders Equity [Abstract]
Common and preferred stock and warrants offering costs	$ 1.7

Common and preferred stock and warrants offering costs.

No definition available.

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Namespace Prefix:	atec_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration