Litigation and Contingencies (Details) $ in Thousands	6 Months Ended	9 Months Ended	12 Months Ended
	Jun. 30, 2009	Sep. 30, 2015 USD ($) case lawsuit settlement	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Dec. 31, 2010 USD ($)	Dec. 31, 2009 USD ($)
Curtailments [Abstract]
Average paid claim reduction due to curtailments (in hundredths)		7.00%	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	$ 2,500,000
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
Percentage of loans covered by CHL Agreement for which consent was received (in hundredths)		89.00%
Maximum exposure above estimate provision for claims paying practices		$ 124,900
Percentage of loans for which consent was not received, percent		11.00%
Maximum exposure associated with other discussions and legal proceedings		$ 202,500
Class action complaint under RESPA [Abstract]
Period of existing captive reinsurance agreement		10 years
Civil penalty				$ 2,650
Other Legal Proceedings [Abstract]
Underwriting remedy expense		$ 1,000	$ 4,000
Class Action Complaint Under RESPA | Pending Litigation
Class action complaint under RESPA [Abstract]
Number of lawsuits | lawsuit		12
Number of cases dismissed | case		12
Insurance-related Assessments
Claims resolved by rescissions [Abstract]
Loss Contingency, Claims Settled, Number | settlement		2