Loss Reserves (Details) $ in Thousands		3 Months Ended		12 Months Ended
		Mar. 31, 2016 USD ($) loan	Mar. 31, 2015 USD ($) loan	Dec. 31, 2015 USD ($) loan	Mar. 31, 2016 USD ($) loan	Dec. 31, 2015 USD ($) loan	Mar. 31, 2015 loan
Loss Reserve [Roll Forward]
Reserve at beginning of period		$ 1,893,402	$ 2,396,807	$ 2,396,807
Less reinsurance recoverable		44,487	57,841	57,841
Net reserve at beginning of period		1,848,915	2,338,966	2,338,966
Losses and LAE incurred in respect of defaults related to [Abstract]
Current year		92,479	109,381
Prior years	[1]	(7,467)	(27,596)
Subtotal		85,012	81,785
Losses and LAE paid in respect of defaults related to [Abstract]
Current year		204	312
Prior years		221,457	231,230
Reinsurance terminations	[2]	(4)	0
Subtotal		221,657	231,542
Net reserve at end of period		1,712,270	2,189,209	1,848,915
Plus reinsurance recoverables		41,119	55,415	44,487
Reserve at end of period		1,753,389	2,244,624	$ 1,893,402
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Prior years	[1]	(7,467)	(27,596)
Prior years		$ 221,457	$ 231,230
Premium refund liability, expected claim payments					$ 99,000	$ 102,000
Primary Default Inventory [Roll Forward]
Default inventory at the beginning of period | loan		62,633	79,901	79,901
New notices | loan		16,731	18,896
Cures | loan		(19,053)	(21,767)
Paids (including those charged to a deductible or captive) | loan		(3,373)	(4,573)
Rescissions and denials | loan		(210)	(221)
Items removed from inventory resulting from settlements (1) | loan	[3]	(1,138)	0
Default inventory at end of period | loan		55,590	72,236	62,633
Loans whose insurance was terminated by agreement to settle coverage | loan		732
Number of loans with previously suspended rescissions included in rescission settlement agreement | loan		406
Pool insurance notice inventory [Abstract]
Historical average period for uncured default to develop into paid claim		12 months
Percent of default inventory in default for more than 36 months		49.00%	53.00%	50.00%
Pool insurance notice inventory (in number of loans) | loan					2,247	2,739	3,350
Aging of the Primary Default Inventory [Abstract]
3 months or less | loan					10,120	13,053	11,604
3 months or less (in hundredths)					18.00%	21.00%	16.00%
4 - 11 months | loan					15,319	15,763	18,940
4 - 11 months (in hundredths)					28.00%	25.00%	26.00%
12 months or more | loan	[4]				30,151	33,817	41,692
12 months or more (in hundredths)	[4]				54.00%	54.00%	58.00%
Total primary default inventory | loan		62,633	79,901	79,901	55,590	62,633	72,236
Total primary default inventory (in hundredths)					100.00%	100.00%	100.00%
Primary claims received inventory included in ending default inventory | loan					2,267	2,769	4,448
Primary claims received inventory included in ending default inventory (in hundredths)					4.00%	4.00%	6.00%
Number of payments delinquent [Abstract]
3 payments or less | loan					16,864	20,360	19,159
3 payments or less (in hundredths)					30.00%	33.00%	27.00%
4 - 11 payments | loan					14,595	15,092	18,372
4 - 11 payments (in hundredths)					26.00%	24.00%	25.00%
12 payments or more | loan					24,131	27,181	34,705
12 payments or more (in hundredths)					44.00%	43.00%	48.00%
Total primary default inventory | loan		62,633	79,901	79,901	55,590	62,633	72,236
Total primary default inventory (in hundredths)					100.00%	100.00%	100.00%
Premium refund liability, expected future rescissions					$ 5,000	$ 7,000
Decrease in estimated claim rate on primary defaults
Losses and LAE incurred in respect of defaults related to [Abstract]
Prior years		$ (26,000)	$ (39,000)
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Prior years		$ (26,000)	$ (39,000)
Percentage of prior year default inventory resolved (in hundredths)		28.00%	24.00%
Increase in estimated severity on primary defaults
Losses and LAE incurred in respect of defaults related to [Abstract]
Prior years		$ 22,000	$ 17,000
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Prior years		22,000	17,000
Change in estimates related to pool reserves, LAE reserves and reinsurance
Losses and LAE incurred in respect of defaults related to [Abstract]
Prior years		(3,000)	(6,000)
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Prior years		(3,000)	(6,000)
Change in estimates related to disputes on claims paying practices and IBNR
Losses and LAE incurred in respect of defaults related to [Abstract]
Prior years			20,000
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Prior years			$ 20,000
Settlements For Claims Paying Practices And Nonperforming Loan Sale
Losses and LAE paid in respect of defaults related to [Abstract]
Prior years		47,000
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Prior years		$ 47,000

[1] A negative number for prior year losses incurred indicates a redundancy of prior year loss reserves.

[2] In a termination or commutation, the reinsurance agreement is cancelled, with no future premium ceded and funds for any incurred but unpaid losses transferred to us. The transferred funds result in an increase in our investment portfolio (including cash and cash equivalents) and a decrease in net losses paid (reduction in losses incurred). In addition, there is an offsetting decrease in the reinsurance recoverable (increase in losses incurred), and thus there is no net impact to losses incurred.

[3] Includes 732 loans whose insurance was terminated by agreement to settle coverage on certain non-performing loans, and 406 loans for which we had previously suspended rescissions and that were included in a rescission settlement agreement. Both agreements became effective in the first quarter of 2016 and neither had a material financial impact in the quarter.

[4] Approximately 49%, 50%, and 53% of the primary default inventory in default for 12 consecutive months or more has been in default for at least 36 consecutive months as of March 31, 2016, December 31, 2015, and March 31, 2015, respectively.