Summary of Significant Accounting Policies (Details) (USD $)	3 Months Ended																12 Months Ended
	Dec. 31, 2012		Sep. 30, 2012		Jun. 30, 2012		Mar. 31, 2012		Dec. 31, 2011		Sep. 30, 2011		Jun. 30, 2011		Mar. 31, 2011		Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Summary of Significant Accounting Policies [Abstract]
Discount rates used for the DCF model, minimum (in hundredths)																	16.87%
Discount rate used for the DCF model, maximum (in hundredths)																	18.35%
Home office and equipment [Abstract]
Accumulated depreciation of home office and equipment	$ 51,300,000								$ 65,200,000								$ 51,300,000		$ 65,200,000		$ 62,900,000
Depreciation expense of home office and equipment																	1,900,000		2,300,000		2,900,000
Loss Reserves [Abstract]
Minimum period for which an insured loan is past due in order for it to be considered in default (in days)																	45 days
Share-Based Compensation [Abstract]
Minimum vesting period for share-based compensation awards																	1 year
Maximum vesting period for share-based compensation awards																	5 years
Earnings per Share [Abstract]
Antidilutive securities excluded from weighted average number of shares (in shares)																	61,700,000		55,600,000		47,400,000
Basic loss per share [Abstract]
Average common shares outstanding (in shares)																	201,892,000		201,019,000		176,406,000
Net loss	(386,691,000)	[1]	(246,942,000)		(273,891,000)		(19,555,000)		(135,294,000)		(165,205,000)		(151,732,000)		(33,661,000)		(927,079,000)		(485,892,000)		(363,735,000)
Basic loss per share (in dollars per share)	$ (1.91)	[1],[2]	$ (1.22)	[2]	$ (1.36)	[2]	$ (0.1)	[2]	$ (0.67)	[1],[2]	$ (0.82)	[2]	$ (0.75)	[2]	$ (0.17)	[2]	$ (4.59)	[2]	$ (2.42)	[2]	$ (2.06)
Diluted loss per share [Abstract]
Weighted-average shares - Basic (in shares)																	201,892,000		201,019,000		176,406,000
Common stock equivalents (in shares)																	0		0		0
Weighted-average shares - Diluted (in shares)																	201,892,000		201,019,000		176,406,000
Net loss	(386,691,000)	[1]	(246,942,000)		(273,891,000)		(19,555,000)		(135,294,000)		(165,205,000)		(151,732,000)		(33,661,000)		(927,079,000)		(485,892,000)		(363,735,000)
Diluted loss per share (in dollars per share)	$ (1.91)	[1],[2]	$ (1.22)	[2]	$ (1.36)	[2]	$ (0.1)	[2]	$ (0.67)	[1],[2]	$ (0.82)	[2]	$ (0.75)	[2]	$ (0.17)	[2]	$ (4.59)	[2]	$ (2.42)	[2]	$ (2.06)
Other comprehensive income (loss) (Before tax) [Abstract]
Change in unrealized gains and losses on investments																	(78,546,000)		31,662,000		(71,308,000)
Amortization related to benefit plans																	(1,221,000)		(19,789,000)		6,390,000
Unrealized foreign currency translation adjustment																	2,452,000		(318,000)		15,615,000
Other comprehensive income (loss)																	(77,315,000)		11,555,000		(49,303,000)
Other comprehensive income (loss) (Tax effect) [Abstract]
Change in unrealized gains and losses on investments																	27,510,000		(10,605,000)		27,220,000
Amortization related to benefit plans																	428,000		6,927,000		(2,236,000)
Unrealized foreign currency translation adjustment																	(859,000)		111,000		(5,479,000)
Other comprehensive income (loss)																	27,079,000		(3,567,000)		19,505,000
Other comprehensive income (loss) (Valuation allowance) [Abstract]
Change in unrealized investment gains and losses, net																	(27,623,000)		0		(24,986,000)
Amortization related to benefit plans																	(428,000)		0		2,236,000
Unrealized foreign currency translation adjustment																	0		0		529,000
Other comprehensive income (loss)																	(28,051,000)		0		(22,221,000)
Other comprehensive income (loss) (Net of tax) [Abstract]
Change in unrealized gains and losses on investment																	(78,659,000)		21,057,000		(69,074,000)
Amortization related to benefit plans																	(1,221,000)		(12,862,000)		6,390,000
Unrealized foreign currency translation adjustment																	1,593,000		(207,000)		10,665,000
Other comprehensive income (loss)																	(78,287,000)		7,988,000		(52,019,000)
Accumulated other comprehensive income [Abstract]
Unrealized gains (losses) on investments	41,541,000								120,087,000								41,541,000		120,087,000
Defined benefit plans	(71,804,000)								(70,582,000)								(71,804,000)		(70,582,000)
Foreign currency translation adjustment	32,747,000								30,294,000								32,747,000		30,294,000
Accumulated other comprehensive income, before tax	2,484,000								79,799,000								2,484,000		79,799,000
Tax Effect	(50,647,000)	[3]							(49,675,000)	[3]							(50,647,000)	[3]	(49,675,000)	[3]
Total accumulated other comprehensive (loss) income	$ (48,163,000)								$ 30,124,000								$ (48,163,000)		$ 30,124,000
Federal statutory income tax benefit rate (in hundredths)																	35.00%		35.00%		35.00%
Participating Securities with Non-forfeitable Rights to Dividends [Member]
Earnings per Share [Abstract]
Antidilutive securities excluded from weighted average number of shares (in shares)																	1,100,000		1,100,000		1,800,000
Home Office [Member]
Home office and equipment [Abstract]
Estimated useful life																	45 years
Equipment [Member]
Home office and equipment [Abstract]
Estimated useful life																	5 years
Data Processing Hardware [Member]
Home office and equipment [Abstract]
Estimated useful life																	3 years

[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".

[2] Due to the use of weighted average shares outstanding when calculating earnings per share, the sum of the quarterly per share data may not equal the per share data for the year.

[3] Tax effect does not approximate 35% due to amounts of tax benefits not provided in various periods due to our tax valuation allowance.