Reinsurance (Details) (USD $)	3 Months Ended									12 Months Ended
	Dec. 31, 2013 Company	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012		Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013 Company	Dec. 31, 2012	Dec. 31, 2011
Reinsurance [Abstract]
Period of existing captive reinsurance agreement										10 years
Percentage of quota share (in hundredths)										30.00%
Percentage of ceding commission (in hundredths)										20.00%
Percentage quota share in addendum (in hundredths)										40.00%
Reinsurance recoverable on loss reserves related to captive agreements	$ 64,000,000				$ 104,000,000					$ 64,000,000	$ 104,000,000
Fair value of trust fund assets under our captive agreements	226,000,000				303,000,000					226,000,000	303,000,000
Fair value of trust fund assets under captive agreements, no reinsurance recoverable on loss reserves	23,000,000				25,000,000					23,000,000	25,000,000
Trust fund assets transferred to us as a result of captive terminations										3,000,000	6,300,000
Number of other mortgage insurers agreeing to similar CFPB settlements	3									3
Premiums Written and Earned [Abstract]
Ceded premiums written, net of profit commission										49,672,000
Ceded premiums earned, net of profit commission										13,821,000
Ceded losses incurred										176,000
Ceding commissions										10,408,000
Premiums earned [Abstract]
Direct										979,078,000	1,065,663,000	1,170,868,000
Assumed										2,074,000	2,425,000	3,891,000
Ceded										(38,101,000)	(34,918,000)	(50,924,000)
Net premiums earned	226,358,000	231,857,000	237,777,000	247,059,000	261,705,000	[1]	266,432,000	242,628,000	262,405,000	943,051,000	1,033,170,000	1,123,835,000
Losses incurred [Abstract]
Direct										863,871,000	2,115,974,000	1,775,122,000
Assumed										2,645,000	6,912,000	5,229,000
Ceded										(27,790,000)	(55,633,000)	(65,644,000)
Net losses incurred	196,055,000	180,189,000	196,274,000	266,208,000	688,636,000	[1]	490,121,000	551,408,000	337,088,000	838,726,000	2,067,253,000	1,714,707,000
Reinsurance agreement addendum, prepaid reinsurance premiums	$ 23,900,000									$ 23,900,000

[1] The results for the fourth quarter of 2012 include a loss of approximately $267 million related to our settlement with Freddie Mac and approximately $100 million related to our probable rescission settlement agreements. See Note 20 – “Litigation and Contingencies.”