Statements of Cash Flows (USD $) In Thousands	6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010
OPERATING ACTIVITIES:
Net income	$ 79,858	$ 83,761
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	7,067	12,102
Change in net fair value adjustment on derivative and hedging activities	80,481	122,910
Net change in fair value adjustments on trading securities	10,594	217
Net change in fair value adjustments on Consolidated Obligation Bonds held at fair value	538	0
Other adjustments	(2,350)	(6,360)
Net change in:
Accrued interest receivable	7,849	11,986
Other assets	3,373	1,781
Accrued interest payable	(17,549)	(77,915)
Other liabilities	(3,673)	(17,226)
Total adjustments	86,330	47,495
Net cash provided by operating activities	166,188	131,256
Net change in:
Interest-bearing deposits	37,864	(83,313)
Securities purchased under agreements to resell	1,250,000	(1,400,000)
Federal funds sold	3,120,000	(3,235,000)
Premises, software, and equipment	(851)	(1,156)
Trading securities:
Net (increase) decrease in short-term	(707,959)	3,800,000
Proceeds from maturities of long-term	157	121
Available-for-sale securities:
Net decrease in short-term	1,950,065	2,769,910
Held-to-maturity securities:
Net increase in short-term	(1,096,664)	(380)
Proceeds from maturities of long-term	1,742,772	1,738,213
Proceeds from sale of long-term	231,748	213,620
Purchases of long-term	(1,126,906)	(1,743,805)
Advances:
Proceeds	113,345,178	114,961,988
Made	(112,407,844)	(111,651,036)
Mortgage loans held for portfolio:
Principal collected	855,095	817,466
Purchases	(642,698)	(251,281)
Net cash provided by investing activities	6,549,957	5,935,347
FINANCING ACTIVITIES:
Net decrease in deposits and pass-through reserves	(228,561)	(499,707)
Net payments on derivative contracts with financing elements	(84,591)	(84,847)
Net proceeds from issuance of Consolidated Obligations:
Discount Notes	326,110,807	288,929,500
Bonds	8,453,290	10,667,974
Payments for maturing and retiring Consolidated Obligations:
Discount Notes	(328,198,046)	(286,598,980)
Bonds	(11,082,717)	(16,808,976)
Proceeds from issuance of capital stock	20,698	65,124
Payments for redemption of mandatorily redeemable capital stock	(33,016)	(286,981)
Cash dividends paid	(69,518)	(72,191)
Net cash used in financing activities	(5,111,654)	(4,689,084)
Net increase in cash and cash equivalents	1,604,491	1,377,519
Cash and cash equivalents at beginning of the period	197,623	1,807,343
Cash and cash equivalents at end of the period	1,802,114	3,184,862
Supplemental Disclosures:
Interest paid	425,063	542,735
AHP payments, net	16,038	15,102
REFCORP assessments paid	$ 21,481	$ 22,873