Share Capital - Stock Option Activity (Parenthetical) (Details) - shares	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock Options exercised for Number of Common Shares for cash	20,576	13,374
Common stock issued for cashless exercise	657	27,507
Cashless exercise of stock options	1,826	71,294

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