| Segment Reporting Disclosure [Text Block] | Segment Reporting Our mortgage insurance and financial guaranty segments are strategic business units that are managed separately on an operating basis. We allocate corporate income and expenses to our mortgage insurance and financial guaranty segments based on either an allocated percentage of time spent or internally allocated capital. We allocate corporate cash and investments to our segments based on internally allocated capital. The results for each segment for each reporting period can cause significant volatility in allocated capital. Prior to January 1, 2011, we also had a third reportable segment—financial services. Our financial services segment had consisted mainly of our ownership interest in Credit-Based Asset Servicing and Securitization LLC ("C-BASS"), which was a credit-based consumer asset business. We wrote off our entire investment in C-BASS in 2007. C-BASS filed for Chapter 11 bankruptcy protection on November 12, 2010, and was subsequently liquidated. Our equity interest in C-BASS, and a related note receivable from C-BASS that had also been previously written off, were extinguished pursuant to the Plan of Liquidation that was confirmed on April 25, 2011. In addition, until May 3, 2010, when we sold our remaining interest therein, our financial services segment included our interest in Sherman Financial Group LLC, a consumer asset and servicing firm specializing in credit card and bankruptcy-plan consumer assets. Consequently, as of January 1, 2011, we no longer had any on-going activity in this reporting segment. Summarized financial information concerning our current and previous operating segments, as of and for the periods indicated, are as follows: | | | | | | | | | | | | | | | | | | Three Months Ended
September 30, | | Nine Months Ended
September 30, | (In thousands) | 2011 | | 2010 | | 2011 | | 2010 | Mortgage Insurance | | | | | | | | Net premiums written—insurance | $ | 178,215 |
| | $ | 174,419 |
| | $ | 523,255 |
| | $ | 499,360 |
| Net premiums earned—insurance | $ | 163,436 |
| | $ | 181,731 |
| | $ | 513,895 |
| | $ | 539,062 |
| Net investment income | 21,642 |
| | 26,658 |
| | 73,328 |
| | 81,561 |
| Net gains on investments | 53,263 |
| | 62,326 |
| | 98,450 |
| | 125,548 |
| Net impairment losses recognized in earnings | (20 | ) | | (34 | ) | | (31 | ) | | (90 | ) | Change in fair value of derivative instruments | 200 |
| | 6,772 |
| | 64 |
| | 5,739 |
| Net gains (losses) on other financial instruments | 2,486 |
| | (6,591 | ) | | 4,321 |
| | (44,764 | ) | Other income | 1,357 |
| | 1,870 |
| | 3,881 |
| | 5,292 |
| Total revenues | 242,364 |
| | 272,732 |
| | 693,908 |
| | 712,348 |
| Provision for losses | 276,599 |
| | 347,800 |
| | 960,564 |
| | 1,304,513 |
| Change in reserve for premium deficiency | (1,942 | ) | | 8,628 |
| | (6,427 | ) | | 43 |
| Policy acquisition costs | 7,834 |
| | 6,444 |
| | 26,651 |
| | 29,061 |
| Other operating expenses | 36,082 |
| | 31,690 |
| | 104,132 |
| | 103,562 |
| Interest expense | 2,015 |
| | 3,251 |
| | 11,950 |
| | 6,920 |
| Total expenses | 320,588 |
| | 397,813 |
| | 1,096,870 |
| | 1,444,099 |
| Equity in net income of affiliates | — |
| | — |
| | — |
| | — |
| Pretax loss | (78,224 | ) | | (125,081 | ) | | (402,962 | ) | | (731,751 | ) | Income tax benefit | (36,033 | ) | | (50,090 | ) | | (27,158 | ) | | (267,700 | ) | Net loss | $ | (42,191 | ) | | $ | (74,991 | ) | | $ | (375,804 | ) | | $ | (464,051 | ) | Cash and investments | $ | 3,176,860 |
| | $ | 3,722,189 |
| | | | | Deferred policy acquisition costs | 47,863 |
| | 37,144 |
| | | | | Total assets | 3,731,978 |
| | 5,293,768 |
| | | | | Unearned premiums | 206,477 |
| | 199,764 |
| | | | | Reserve for losses and LAE | 3,214,854 |
| | 3,504,181 |
| | | | | VIE debt | 31,164 |
| | 156,811 |
| | | | | Derivative liabilities | — |
| | 178 |
| | | | |
| | | | | | | | | | | | | | | | | | Three Months Ended
September 30, | | Nine Months Ended
September 30, | (In thousands) | 2011 | | 2010 | | 2011 | | 2010 | Financial Guaranty | | | | | | | | Net premiums written—insurance | $ | 72 |
| | $ | 388 |
| | $ | (9,441 | ) | | $ | (9,151 | ) | Net premiums earned—insurance | $ | 16,219 |
| | $ | 22,206 |
| | $ | 57,717 |
| | $ | 66,589 |
| Net investment income | 17,121 |
| | 19,896 |
| | 51,498 |
| | 58,970 |
| Net gains on investments | 28,377 |
| | 31,932 |
| | 64,861 |
| | 83,920 |
| Net impairment losses recognized in earnings | — |
| | — |
| | — |
| | — |
| Change in fair value of derivative instruments | 125,808 |
| | 223,011 |
| | 558,562 |
| | (378,516 | ) | Net gains (losses) on other financial instruments | 78,116 |
| | 11,473 |
| | 156,579 |
| | (115,118 | ) | Other income | 47 |
| | 81 |
| | 167 |
| | 299 |
| Total revenues | 265,688 |
| | 308,599 |
| | 889,384 |
| | (283,856 | ) | Provision for losses | (27,001 | ) | | (3,411 | ) | | (20,027 | ) | | 18,922 |
| Change in reserve for premium deficiency | — |
| | — |
| | — |
| | — |
| Policy acquisition costs | 3,615 |
| | 4,610 |
| | 13,316 |
| | 13,658 |
| Other operating expenses | 9,158 |
| | 11,362 |
| | 33,281 |
| | 39,511 |
| Interest expense | 12,079 |
| | 6,251 |
| | 35,247 |
| | 21,631 |
| Total expenses | (2,149 | ) | | 18,812 |
| | 61,817 |
| | 93,722 |
| Equity in net income of affiliates | — |
| | — |
| | 65 |
| | 78 |
| Pretax income (loss) | 267,837 |
| | 289,787 |
| | 827,632 |
| | (377,500 | ) | Income tax provision (benefit) | 42,078 |
| | 102,611 |
| | 28,139 |
| | (136,278 | ) | Net income (loss) | $ | 225,759 |
| | $ | 187,176 |
| | $ | 799,493 |
| | $ | (241,222 | ) | Cash and investments | $ | 2,759,726 |
| | $ | 2,716,715 |
| | | | | Deferred policy acquisition costs | 91,099 |
| | 109,331 |
| | | | | Total assets | 3,514,307 |
| | 3,257,829 |
| | | | | Unearned premiums | 421,923 |
| | 507,501 |
| | | | | Reserve for losses and LAE | 45,702 |
| | 88,792 |
| | | | | VIE debt | 242,215 |
| | 339,482 |
| | | | | Derivative liabilities | 188,921 |
| | 530,510 |
| | | | |
| | | | | (In thousands) | Nine Months Ended
September 30, 2010 | Financial Services | | Net premiums written—insurance | $ | — |
| Net premiums earned—insurance | $ | — |
| Net investment income | — |
| Net gains on investments | — |
| Net impairment losses recognized in earnings | — |
| Change in fair value of derivative instruments | — |
| Net gains (losses) on other financial instruments | — |
| Gain on sale of affiliate | 34,815 |
| Other income | 63 |
| Total revenues | 34,878 |
| Provision for losses | — |
| Change in reserve for premium deficiency | — |
| Policy acquisition costs | — |
| Other operating expenses | 200 |
| Interest expense | — |
| Total expenses | 200 |
| Equity in net income of affiliates | 14,590 |
| Pretax income | 49,268 |
| Income tax provision | 17,245 |
| Net income | $ | 32,023 |
| Cash and investments | | Deferred policy acquisition costs | | Total assets | | Unearned premiums | | Reserve for losses and LAE | | VIE debt | | Derivative liabilities | |
A reconciliation of segment net income (loss) to consolidated net income (loss) is as follows: | | | | | | | | | | | | | | | | | | Three Months Ended
September 30, | | Nine Months Ended
September 30, | (In thousands) | 2011 | | 2010 | | 2011 | | 2010 | Consolidated | | | | | | | | Net income (loss): | | | | | | | | Mortgage Insurance | $ | (42,191 | ) | | $ | (74,991 | ) | | $ | (375,804 | ) | | $ | (464,051 | ) | Financial Guaranty | 225,759 |
| | 187,176 |
| | 799,493 |
| | (241,222 | ) | Financial Services | — |
| | — |
| | — |
| | 32,023 |
| Total | $ | 183,568 |
| | $ | 112,185 |
| | $ | 423,689 |
| | $ | (673,250 | ) |
|