Reduced percentage of common stock own by beneficial owner due to sell or transfer.

No definition available.

Name:	wetf_ReducedPercentageOfCommonStockOwnByBeneficialOwnerDueToSellOrTransfer
Namespace Prefix:	wetf_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

ETF shareholder proxy solicitation (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
ETF Shareholder Proxy Solicitation (Textual) [Abstract]
Percentage of common stock own by beneficial owner			25.10%
Reduced percentage of common stock own by beneficial owner due to sell or transfer			25.00%
ETF shareholder proxy			$ 3,264