Share Capital - Stock Option Activity (Parenthetical) (Details)	12 Months Ended
Dec. 31, 2015 shares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock Options exercised for Number of Common Shares for cash	70,438
Common stock issued for cashless exercise	133,565
Cashless exercise of stock options	199,816

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