Litigation and Contingencies (Details) (USD $)	3 Months Ended	6 Months Ended	12 Months Ended
	Mar. 31, 2015 Case	Jun. 30, 2009	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2010	Dec. 31, 2009
Curtailments [Abstract]
Average paid claim reduction due to curtailments (in hundredths)	8.20%		6.70%
Number of days after claim paid within which objection must be received for review	90 days
Claims resolved by rescissions [Abstract]
Percentage of claims received in a quarter resolved by rescission, lower range limit (in hundredths)	5.00%
Percentage of claims received in a quarter resolved by rescission, upper range limit (in hundredths)		28.00%
Mitigation of incurred losses by rescission of policies					$ 200,000,000	$ 2,500,000,000
Statute of limitations to bring legal proceedings disputing right to rescind coverage	3 years
Statute of limitations to bring legal proceedings after notice of rescission	2 years
Maximum exposure above estimate provision for claims paying practices	441,000,000
Exposure from claims paying practices related to Countrywide matter (in hundredths)	72.00%
Maximum exposure associated with other discussions and legal proceedings	29,000,000
Class action complaint under RESPA [Abstract]
Number of cases dismissed	5
Period of existing captive reinsurance agreement	10 years
Civil penalty				2,650,000
Other Legal Proceedings [Abstract]
Underwriting remedy expense	0		4,000,000	5,000,000
Class Action Complaint Under RESPA [Member] | Pending Litigation [Member]
Class action complaint under RESPA [Abstract]
Number of lawsuits	12
Number of cases dismissed	7
Countrywide Dispute [Member] | Pending Litigation [Member]
Claims resolved by rescissions [Abstract]
Amount of damages sought	$ 700,000,000
Lawsuits Alleging Improper Recording And Foreclosure Activities By MERS [Member] | Pending Litigation [Member]
Lawsuits alleging improper recording and foreclosure activities by MERS [Abstract]
Number of lawsuits naming non-insurance subsidiary as defendant	8
Number of lawsuits naming subsidiary as defendant that were dismissed	7