<?xml version="1.0" encoding="UTF-8"?>
<informationTable
	xsi:schemaLocation="http://www.sec.gov/edgar/document/thirteenf/informationtable eis_13FDocument.xsd"
	xmlns="http://www.sec.gov/edgar/document/thirteenf/informationtable"
	xmlns:n1="http://www.sec.gov/edgar/document/thirteenf/informationtable"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
	<infoTable>
		<nameOfIssuer>HORIZON GLOBAL CORP</nameOfIssuer>
		<titleOfClass>COM</titleOfClass>
		<cusip>44052W104</cusip>
		<value>10580</value>
		<shrsOrPrnAmt>
			<sshPrnamt>841000</sshPrnamt>
			<sshPrnamtType>SH</sshPrnamtType>
		</shrsOrPrnAmt>
		<investmentDiscretion>DFND</investmentDiscretion>
		<votingAuthority>
			<Sole>0</Sole>
			<Shared>841000</Shared>
			<None>0</None>
		</votingAuthority>
	</infoTable>
	<infoTable>
		<nameOfIssuer>INTERACTIVE BROKERS GRO-CL A</nameOfIssuer>
		<titleOfClass>COM</titleOfClass>
		<cusip>45841N107</cusip>
		<value>19027</value>
		<shrsOrPrnAmt>
			<sshPrnamt>483890</sshPrnamt>
			<sshPrnamtType>SH</sshPrnamtType>
		</shrsOrPrnAmt>
		<investmentDiscretion>DFND</investmentDiscretion>
		<votingAuthority>
			<Sole>0</Sole>
			<Shared>483890</Shared>
			<None>0</None>
		</votingAuthority>
	</infoTable>
</informationTable>
