Statements of Convertible Preferred Stock (Parenthetical) $ in Thousands	12 Months Ended
Dec. 31, 2017 USD ($)
Series A-2
Stock issuance costs capitalized	$ 21
Series B
Stock issuance costs capitalized	$ 243

The amount of stock issuance costs capitalized during the period.

No definition available.

Name:	aptx_StockIssuanceCostsCapitalized
Namespace Prefix:	aptx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration