Loss Reserves (Details) (USD $)	12 Months Ended
	Dec. 31, 2013 Loan		Dec. 31, 2012 Loan		Dec. 31, 2011 Loan		Dec. 31, 2010		Dec. 31, 2009
Loss Reserve [Roll Forward]
Reserve at beginning of period	$ 4,056,843,000		$ 4,557,512,000		$ 5,884,171,000
Less reinsurance recoverable	104,848,000		154,607,000		275,290,000
Net reserve at beginning of year	3,951,995,000	[1],[2]	4,402,905,000	[1],[2]	5,608,881,000	[1]
Losses and LAE incurred in respect of default notices received in [Abstract]
Current year	898,413,000		1,494,133,000		1,814,035,000
Prior years	(59,687,000)	[3]	573,120,000	[3]	(99,328,000)	[3]
Subtotal	838,726,000	[4]	2,067,253,000	[4]	1,714,707,000	[4]
Losses and LAE paid in respect of default notices received in [Abstract]
Current year	73,470,000		134,509,000		121,383,000
Prior years	1,722,923,000	[5]	2,389,985,000	[5]	2,838,069,000	[5]
Reinsurance terminations	(2,988,000)	[6]	(6,331,000)	[6]	(38,769,000)	[6]
Subtotal	1,793,405,000	[7]	2,518,163,000	[7]	2,920,683,000	[7]
Net reserve at end of period	2,997,316,000	[2]	3,951,995,000	[1],[2]	4,402,905,000	[1],[2]	5,608,881,000	[1]
Plus reinsurance recoverables	64,085,000		104,848,000		154,607,000		275,290,000
Reserve at end of period	3,061,401,000		4,056,843,000		4,557,512,000		5,884,171,000
Loss reserve reduction from rescission	100,000,000		200,000,000		700,000,000		1,300,000,000
Reduction in estimated rescissions			200,000,000
Paid losses mitigated by rescission amount	100,000,000		300,000,000		600,000,000
Payment under the Freddie Mac settlement agreement	41,000,000		100,000,000
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Change in loss reserves	(60,000,000)		573,000,000		(99,000,000)
Obligations under the disputed policies			267,000,000
Historical average period for uncured default to develop into paid claim	12 months
Premium refund liability, expected claim payments	131,000,000		134,000,000
Primary Default Inventory [Roll Forward]
Default inventory at beginning of period	139,845		175,639		214,724
New Notices	106,823		133,232		169,305
Cures	(104,390)		(120,248)		(149,643)
Paids (including those charged to a deductible or captive)	(34,738)		(45,741)		(51,138)
Rescissions and denials	(1,939)		(3,037)		(7,609)
Items removed from inventory resulting from the Countrywide settlement on GSE loans	(2,273)		0		0
Default inventory at end of period	103,328		139,845		175,639		214,724
Number of rescindable loans affected by Company's decision to voluntarily suspend rescissions	1,500
Pool insurance notice inventory [Abstract]
Pool insurance notice inventory (in number of loans)	6,563		8,594		32,971
Aging of the Primary Default Inventory [Abstract]
3 months or less	18,941		23,282		31,456
3 months or less (in hundredths)	18.00%		17.00%		18.00%
4 - 11 months	24,514		34,688		46,352
4 - 11 months (in hundredths)	24.00%		25.00%		26.00%
12 months or more	59,873		81,875		97,831
12 months or more (in hundredths)	58.00%		58.00%		56.00%
Total primary default inventory	103,328		139,845		175,639		214,724
Total primary default inventory (in hundredths)	100.00%		100.00%		100.00%
Primary claims received inventory included in ending default inventory	6,948	[8]	11,731	[8]	12,610	[8]
Primary claims received inventory included in ending default inventory (in hundredths)	7.00%	[8]	8.00%	[8]	7.00%	[8]
Number of payments delinquent [Abstract]
3 payments or less	28,095		34,245		42,804
3 payments or less (in hundredths)	27.00%		24.00%		24.00%
4 - 11 payments	24,605		34,458		47,864
4 - 11 payments (in hundredths)	24.00%		25.00%		27.00%
12 payments or more	50,628		71,142		84,971
12 payments or more (in hundredths)	49.00%		51.00%		49.00%
Total primary default inventory	103,328		139,845		175,639		214,724
Total primary default inventory (in hundredths)	100.00%		100.00%		100.00%
Mitigation of incurred losses by rescission of policies	0		0		0		200,000,000		2,500,000,000
Premium refund liability, expected future rescissions	15,000,000		18,000,000
Loss reserve reduction from rescission	100,000,000		200,000,000		700,000,000		1,300,000,000
Freddie Mac's disagreement on aggregate loss limit [Member]
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Obligations under the disputed policies			267,500,000
Amount paid as per settlement agreement			100,000,000
Remaining amount of unpaid settlement agreement			167,500,000
Number of installments to pay settlement agreement amount			48
Pool Policy Settlement [Member]
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Change in loss reserves	0	[9]	267,000,000	[9]	0	[9]
Increase (Decrease) in Estimated Claim Rate On primary Defaults [Member]
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Change in loss reserves	10,000,000		260,000,000		200,000,000
Percentage of prior year default inventory resolved (in hundredths)	59.00%		55.00%		57.00%
Decrease in Estimated Severity, Primary Defaults [Member]
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Change in loss reserves	(50,000,000)		(70,000,000)		(165,000,000)
Change In Estimates Related to Pool Reserves, LAE Reserves, Reinsurance and Other [Member]
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Change in loss reserves	(20,000,000)	[10]	116,000,000	[10]	(134,000,000)	[10]
Increase (Decrease) Related To Probable Settlements and LAE Reserves [Member]
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Change in loss reserves			$ 100,000,000		$ (114,000,000)

[1] At December 31, 2012, 2011 and 2010 the estimated reduction in loss reserves related to rescissions approximated $0.2 billion, $0.7 billion and $1.3 billion, respectively.

[2] At December 31, 2013, 2012 and 2011 the estimated reduction in loss reserves related to rescissions approximated $0.1 billion, $0.2 billion and $0.7 billion, respectively.

[3] A negative number for prior year losses incurred indicates a redundancy of prior year loss reserves, and a positive number for prior year losses incurred indicates a deficiency of prior year loss reserves. See table below regarding prior year loss development.

[4] Rescissions did not have a significant impact on our losses incurred in 2013 or 2011. Our estimated rescissions were reduced by approximately $0.2 billion in 2012 due to probable settlement agreements (See Note 20 – “Litigation and Contingencies”), other rescissions had no significant impact on our losses incurred in 2012.

[5] 2013 and 2012, include $41 million and $100 million, respectively, paid under the terms of our settlement agreement with Freddie Mac as discussed below.

[6] In a termination, 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 to 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. (See Note 11 – “Reinsurance”)

[7] Rescissions mitigated our paid losses by an estimated $0.1 billion, $0.3 billion and $0.6 billion in 2013, 2012 and 2011, respectively, which excludes amounts that may have been applied to a deductible.

[8] Our claims received inventory includes suspended rescissions, as we have voluntarily suspended rescissions of coverage related to loans that we believed would be included in a potential resolution. As of December 31, 2013, rescissions of coverage on approximately 1,500 loans had been voluntarily suspended.

[9] See below for a discussion of our settlement with Freddie Mac.

[10] Includes approximately $100 million related to probable settlements regarding our claims paying practices in 2012 and ($114) million related to LAE reserves in 2011.