CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Unaudited) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
Sep. 30, 2019	Mar. 31, 2018
Statement Of Stockholders Equity [Abstract]
Common and preferred stock and warrants offering costs		$ 2,600
Common stock public offering cost	$ 3,689

Common and preferred stock and warrants offering costs.

No definition available.

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