CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Cash flows from operating activities:
Net income	$ 64,311	$ 48,511
Adjustments to reconcile net income to net cash provided by operating activities:
Net amortization of deferred gains, premiums, and discounts on loans, investments, Farmer Mac Guaranteed Securities, and USDA Securities	1,701	1,343
Amortization of debt premiums, discounts and issuance costs	17,078	24,789
Net change in fair value of trading securities, hedged assets, and financial derivatives	(12,232)	1,672
Gains on sale of real estate owned	(784)	(15)
Total provision for losses	1,294	490
Excess Tax Benefits from Share-Based Compensation	1,170	0
Deferred income taxes	1,910	(1,270)
Other Noncash Income (Expense)	11	9
Stock-based compensation expense	2,597	2,565
Proceeds from repayment of trading investment securities	0	2,212
Proceeds from repayment of loans purchased as held for sale	54,919	67,506
Net change in:
Interest receivable	12,678	26,172
Guarantee and commitment fees receivable	226	534
Other assets	(109)	(46,832)
Accrued interest payable	12,104	(7,351)
Other liabilities	435	507
Net cash provided by operating activities	157,309	120,842
Cash flows from investing activities:
Purchases of loans held for investment	(1,047,001)	(762,018)
Purchases of defaulted loans	(3,458)	(2,516)
Proceeds from repayment of loans purchased as held for investment	368,826	333,920
Proceeds from sale of Farmer Mac Guaranteed Securities	404,246	457,369
Proceeds from sale of real estate owned	6,464	295
Net cash used by investing activities	(1,777,246)	(930,044)
Cash flows from financing activities:
Excess tax benefits related to stock-based awards	0	408
Payments to third parties on debt securities of consolidated trusts	(86,582)	(71,806)
Proceeds from common stock issuance	235	405
Tax payments related to share-based awards	(2,283)	(1,975)
Investment in subsidiary - non-controlling interest	0	53
Dividends paid on common and preferred stock	(21,321)	(18,031)
Net cash provided/(used) by financing activities	1,721,472	(87,301)
Net increase in cash and cash equivalents	101,535	(896,503)
Cash and cash equivalents at beginning of period	265,229	1,210,084
Cash and cash equivalents at end of period	366,764	313,581
Medium-term Notes [Member]
Cash flows from financing activities:
Proceeds from issuance of discount notes and medium-term notes	7,160,298	4,763,631
Payments to redeem discount notes and medium-term notes	(3,416,300)	(3,103,800)
Discount Notes [Member]
Cash flows from financing activities:
Proceeds from issuance of discount notes and medium-term notes	40,262,122	77,411,229
Payments to redeem discount notes and medium-term notes	(42,174,697)	(79,058,129)
Investment Securities [Member]
Cash flows from investing activities:
Purchases of available-for-sale investment securities and Farmer Mac Guaranteed Securities and USDA Guaranteed Securities	(614,423)	(1,365,314)
Proceeds from repayment of available-for-sale investment securities, Farmer Mac Guaranteed Securities and USDA Guaranteed Securities	895,497	957,973
Proceeds from sale of available-for-sale investment securities	5,089	186,769
Farmer Mac Guaranteed Securities and USDA Securities [Member]
Cash flows from investing activities:
Purchases of available-for-sale investment securities and Farmer Mac Guaranteed Securities and USDA Guaranteed Securities	(2,580,229)	(2,203,574)
Proceeds from repayment of available-for-sale investment securities, Farmer Mac Guaranteed Securities and USDA Guaranteed Securities	787,743	1,467,052
Common Class C, Non-Voting [Member]
Cash flows from financing activities:
Common stock repurchased	$ 0	$ (9,286)