Transactions with Related Parties (Statement of Income Effects) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2012		Sep. 30, 2011		Sep. 30, 2012		Sep. 30, 2011
Related Party Transaction [Line Items]
Federal funds sold	$ 838		$ 738		$ 1,874		$ 3,434
Interest income on advances	66,122		59,707		197,027		185,456
Prepayment fees on advances, net	2,230		1,415		14,266		1,644
Interest income on MPF loans	41,284		49,880		128,788		153,863
Interest expense on deposits	138		96		415		346
Total MPF loan volume purchased					397,646		192,675
Principal Owner [Member]
Related Party Transaction [Line Items]
Interest income on advances	30,554	[1]	25,829	[1]	100,298	[1]	80,509	[1]
Interest income on MPF loans	32,416		40,779		102,813		128,328
Total MPF loan volume purchased	$ 57,566		$ 80		$ 89,142		$ 80

[1] For the three and nine months ended September 30, 2012 respectively, it includes contractual interest income of $87.3 million and $329.8 million, net interest settlements on derivatives in fair value hedge relationships of $(55.6) million and $(215.3) million and total amortization of basis adjustments of $(1.1) million and $(14.1) million. For the three and nine months ended September 30, 2011 respectively, it includes contractual interest income of $128.9 million and $393.8 million, net interest settlements on derivatives in fair value hedge relationships of $(94.3) million and $(287.0) million and total amortization of basis adjustments of $(8.8) million and $