Consolidated Statements of Equity (Parenthetical) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statement of Stockholders' Equity [Abstract]
Comprehensive income attributable to redeemable noncontrolling interests	$ 92	$ 73	$ 34

Comprehensive Income (Loss), Net of Tax, Portion Attributable to Redeemable Noncontrolling Interest

No definition available.

Name:	mhfi_ComprehensiveIncomeLossNetOfTaxPortionAttributableToRedeemableNoncontrollingInterest
Namespace Prefix:	mhfi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration