Consolidated Obligations Contractual Maturity or Next Call Date (Details) (Unsecured Debt [Member], USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Consolidated Obligations by Contractual Maturity or Next Call Date [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Next Rolling Twelve Months	$ 13,138,535	$ 9,618,500
Long-term Debt, Maturities, Repayments of Principal in Rolling Year Two	3,010,800	10,277,745
Long-term Debt, Maturities, Repayments of Principal in Rolling Year Three	1,072,000	1,619,985
Long-term Debt, Maturities, Repayments of Principal in Rolling Year Four	445,000	450,000
Long-term Debt, Maturities, Repayments of Principal in Rolling Year Five	1,207,000	425,000
Long-term Debt, Maturities, Repayments of Principal in Rolling after Year Five	3,212,075	3,182,000
Debt, Gross	22,085,410	25,573,230
Earlier of Contractual Maturity or Next Call Date [Member]
Consolidated Obligations by Contractual Maturity or Next Call Date [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Next Rolling Twelve Months	18,055,610	13,813,500
Long-term Debt, Maturities, Repayments of Principal in Rolling Year Two	2,770,800	9,467,745
Long-term Debt, Maturities, Repayments of Principal in Rolling Year Three	732,000	1,459,985
Long-term Debt, Maturities, Repayments of Principal in Rolling Year Four	50,000	430,000
Long-term Debt, Maturities, Repayments of Principal in Rolling Year Five	397,000	0
Long-term Debt, Maturities, Repayments of Principal in Rolling after Year Five	80,000	402,000
Debt, Gross	$ 22,085,410	$ 25,573,230