Share Capital - Stock Option Activity (Parenthetical) (Details) - shares	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock Options exercised for Number of Common Shares for cash	23,472	36,007
Common stock issued for cashless exercise	863	34,524
Cashless exercise of stock options	2,391	82,712

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