Consolidated Obligations (Consolidated Obligation Bonds Noncallable and Callable) (Details) (Consolidated Obligation Bonds [Member], USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Schedule of Short-term and Long-term Debt [Line Items]
Par value of consolidated bonds	$ 33,248,956	$ 35,133,965
Non Callable [Member]
Schedule of Short-term and Long-term Debt [Line Items]
Par value of consolidated bonds	28,092,456	32,250,465
Callable [Member]
Schedule of Short-term and Long-term Debt [Line Items]
Par value of consolidated bonds	$ 5,156,500	$ 2,883,500