Share Capital - Stock Option Activity (Parenthetical) (Details) - shares	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock Options exercised for Number of Common Shares for cash	10,715	23,472
Common stock issued for cashless exercise	85,660	863
Cashless exercise of stock options	142,327	2,391

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