Goodwill	12 Months Ended
Dec. 31, 2011
Goodwill [Abstract]
Goodwill	Note 13: Goodwill Under the accounting guidance for goodwill and other intangible assets, goodwill is tested for impairment at least annually or when events indicate that an impairment may exist. The Company performed its annual impairment testing of goodwill, which related to its U.S. public finance insurance reporting unit, as of January 1, 2012. As of January 1, 2012, the fair value of the Company's U.S. public finance reporting unit did not exceed its carrying value, indicating that goodwill was potentially impaired. The fair value as of January 1, 2012 reflected the prolonged delay on the resolution of the litigation challenging the establishment of National, which adversely impacted the timing of writing new business, a key trigger for assessing goodwill impairment. As a result, in 2011, the Company recorded an impairment loss of $31 million, representing the full amount of goodwill, within "Other net realized gains (losses)" in its consolidated statements of operations. In performing this evaluation, the Company calculated the fair value of its U.S. public finance reporting unit utilizing discounted cash flow modeling. The inputs to the Company's valuation model included its estimates of market participant assumptions.

Note 13: Goodwill

Under the accounting guidance for goodwill and other intangible assets, goodwill is tested for impairment at least annually or when events indicate that an impairment may exist. The Company performed its annual impairment testing of goodwill, which related to its U.S. public finance insurance reporting unit, as of January 1, 2012.

As of January 1, 2012, the fair value of the Company's U.S. public finance reporting unit did not exceed its carrying value, indicating that goodwill was potentially impaired. The fair value as of January 1, 2012 reflected the prolonged delay on the resolution of the litigation challenging the establishment of National, which adversely impacted the timing of writing new business, a key trigger for assessing goodwill impairment. As a result, in 2011, the Company recorded an impairment loss of $31 million, representing the full amount of goodwill, within "Other net realized gains (losses)" in its consolidated statements of operations. In performing this evaluation, the Company calculated the fair value of its U.S. public finance reporting unit utilizing discounted cash flow modeling. The inputs to the Company's valuation model included its estimates of market participant assumptions.