Financial Guarantees Financial Guarantees and Maximum Recovery (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014		Dec. 31, 2013
Financial Guarantees and Maximum Recovery [Line Items]
Maximum Exposure	$ 48,644	[1]	$ 49,915	[1]
Guarantor Obligations	467		485
Maximum Recovery	14,963	[2]	15,066	[2]
Non-consolidated Fannie Mae MBS [Member] | Unconsolidated VIEs [Member]
Financial Guarantees and Maximum Recovery [Line Items]
Maximum Exposure	18,799	[1]	19,317	[1]
Guarantor Obligations	226		232
Maximum Recovery	10,318	[2]	10,541	[2]
Other guaranty arrangements [Member] | Unconsolidated VIEs [Member]
Financial Guarantees and Maximum Recovery [Line Items]
Maximum Exposure	29,845	[1],[3]	30,598	[1],[3]
Guarantor Obligations	241	[3]	253	[3]
Maximum Recovery	$ 4,645	[2],[3]	$ 4,525	[2],[3]

[1] Primarily consists of the unpaid principal balance of the underlying mortgage loans.

[2] Recoverability of such credit enhancements and recourse is subject to, among other factors, our mortgage insurers’ and financial guarantors’ ability to meet their obligations to us. For information on our mortgage insurers, see “Note 14, Concentrations of Credit Risk.”

[3] Primarily consists of credit enhancements, long-term standby commitments, and our commitment under the TCLF program.