Statements of Capital (Unaudited) (USD $) In Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2011		Jun. 30, 2010		Jun. 30, 2011		Jun. 30, 2010
Beginning Balance					$ 5,144,369		$ 5,603,291
Proceeds from sale of capital stock					1,332,486		859,266
Redemption of capital stock					(1,200,255)		(1,208,434)
Shares reclassified to mandatorily redeemable capital stock					(3,349)		(30,266)
Cash dividends ($2.46 and $2.57 per share for 2010 and 2011 respectively) on capital stock					(115,400)		(122,651)
Net Income	53,311		56,665		124,291		110,305
Net change in Accumulated other comprehensive income (loss):
Non-credit portion of OTTI on held-to-maturity securities, net of accretion					6,726		8,693
Net unrealized gains/losses on available-for-sale securities					(4,352)		23,591
Hedging activities					(5,627)		3,069
Ending Balance	5,278,889		5,246,864		5,278,889		5,246,864
Capital Stock Class B [Member]
Beginning Balance					4,528,962	[1]	5,058,956	[1]
Beginning Balance, shares					45,290	[1]	50,590	[1]
Proceeds from sale of capital stock					1,332,486	[1]	859,266	[1]
Proceeds from sale of capital stock, shares					13,324	[1]	8,592	[1]
Redemption of capital stock					(1,200,255)	[1]	(1,208,434)	[1]
Redemption of capital stock, shares					(12,003)	[1]	(12,084)	[1]
Shares reclassified to mandatorily redeemable capital stock					(3,349)	[1]	(30,266)
Shares reclassified to mandatorily redeemable capital stock, shares					(33)	[1]	(303)
Net change in Accumulated other comprehensive income (loss):
Ending Balance	4,657,844	[1]	4,679,522	[1]	4,657,844	[1]	4,679,522	[1]
Ending Balance, shares	46,578	[1]	46,795	[1]	46,578	[1]	46,795	[1]
Retained Earnings
Beginning Balance					712,091		688,874
Cash dividends ($2.46 and $2.57 per share for 2010 and 2011 respectively) on capital stock					(115,400)		(122,651)
Net Income					124,291		110,305
Net change in Accumulated other comprehensive income (loss):
Ending Balance	720,982		676,528		720,982		676,528
Accumulated Other Comprehensive Income (Loss)
Beginning Balance					(96,684)		(144,539)
Net change in Accumulated other comprehensive income (loss):
Non-credit portion of OTTI on held-to-maturity securities, net of accretion					6,726		8,693
Net unrealized gains/losses on available-for-sale securities					(4,352)		23,591
Hedging activities					(5,627)		3,069
Ending Balance	(99,937)		(109,186)		(99,937)		(109,186)
Total Comprehensive Income (Loss)
Net Income					124,291		110,305
Net change in Accumulated other comprehensive income (loss):
Non-credit portion of OTTI on held-to-maturity securities, net of accretion					6,726		8,693
Net unrealized gains/losses on available-for-sale securities					(4,352)		23,591
Hedging activities					(5,627)		3,069
Total comprehensive income					$ 121,038		$ 145,658

[1] Putable stock