Share Capital - Stock Option Activity (Parenthetical) (Details) - shares	6 Months Ended
Jun. 30, 2021	Jun. 30, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock Options exercised for Number of Common Shares for cash	58,179	10,715
Common stock issued for cashless exercise	179,129	85,660
Cashless exercise of stock options	286,555	142,327

Number of common stock issued in exchange for share options (or share units) exercised via net exercise (cashless) method during the current period.

No definition available.

Name:	xene_CommonStockIssuedForCashlessExercise
Namespace Prefix:	xene_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration