ETF Shareholder Proxy Solicitation - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2012
Equity [Abstract]
Percentage of common stock own by beneficial owner	25.50%
Reduced percentage of common stock owned by beneficial owner due to sell or transfer	25.00%
Threshold percentage of ownership presumes change in control	25.00%
ETF shareholders proxy	$ 3,264

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