<?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>VANGUARD BD INDEX FD INC</nameOfIssuer>
		<titleOfClass>TOTAL BND MRKT</titleOfClass>
		<cusip>921937835</cusip>
		<value>38132</value>
		<shrsOrPrnAmt>
			<sshPrnamt>454829</sshPrnamt>
			<sshPrnamtType>SH</sshPrnamtType>
		</shrsOrPrnAmt>
		<investmentDiscretion>SOLE</investmentDiscretion>
		<votingAuthority>
			<Sole>454829</Sole>
			<Shared>0</Shared>
			<None>0</None>
		</votingAuthority>
	</infoTable>
</informationTable>
