Credit Risk (Details Textuals) (USD $)	6 Months Ended
	Jun. 30, 2011	Dec. 31, 2010	Jun. 30, 2010	Dec. 31, 2009
Credit Risk (Textuals) [Abstract]
Number of days with in which loans are sold to investors	60 days
Number of Loans in Foreclosure	16,913	18,554
Unpaid principal balances	$ 3,000,000,000	$ 3,300,000,000
Loan repurchase and indemnification amount of loans sold	197,000,000
Percentage of identified breach of representation and warranty provisions	15.00%
Liabilities for probable losses related to repurchase and indemnification obligations	88,000,000	74,000,000
Contractual reinsurance period for each pool	10 years
Weighted average reinsurance period	4.5
Securities in trust included in Restricted cash, cash equivalents and investments	246,000,000
Unpaid reinsurance losses outstanding	8,000,000
Other liabilities associated with mortgage reinsurance activities	97,000,000	113,000,000	128,000,000	108,000,000
Direct finance leases greater than 90 days past due	20,000,000	19,000,000
Maximum amount of loans in capitalized portfolio	142,436,000,000
Direct financing leases, Accrued	18,000,000	16,000,000
Allowance for credit losses related to direct financing receivables	$ 2,000,000	$ 3,000,000
Guarantor Obligations, Maximum Exposure Inestimable	The maximum exposure to representation and warranty provisions exceeds the amount of loans in the capitalized portfolio of $142.4 billion; however, the range of total possible losses cannot be estimated because the Company does not service all of the loans for which it has provided representations or warranties.