CONSOLIDATED STATEMENTS OF EQUITY Statement - USD ($) $ in Thousands	Total	Common Class C, Non-Voting [Member]	Preferred Stock [Member]	Preferred Stock [Member] Common Class C, Non-Voting [Member]	Common Stock [Member]	Common Stock [Member] Common Class C, Non-Voting [Member]	Additional Paid-in Capital [Member]	Additional Paid-in Capital [Member] Common Class C, Non-Voting [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Accumulated Other Comprehensive Income (Loss) [Member] Common Class C, Non-Voting [Member]	Retained Earnings [Member]	Retained Earnings [Member] Common Class C, Non-Voting [Member]	Noncontrolling Interest [Member]	Noncontrolling Interest [Member] Common Class C, Non-Voting [Member]
Beginning Balance (Shares Outstanding) at Dec. 31, 2015			8,400,000		10,687,000
Beginning Balance at Dec. 31, 2015	$ 553,720		$ 204,759		$ 10,687		$ 117,862		$ (11,019)		$ 231,228		$ 203
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Attributable to Farmer Mac	28,914		0		0		0		0		28,914		0
Less: Net loss attributable to non-controlling interest	44		0		0		0		0		0		(44)
Other comprehensive income, net of tax	23,403		0		0		0		23,403		0		0
Preferred stock	(6,591)		0		0		0		0		(6,591)		0
Common stock	(5,421)		0		0		0		0		(5,421)		0
Stock Issued During Period, Shares, New Issues				0		80,000
Stock Issued During Period, Value, New Issues		$ 213		$ 0		$ 80		$ 133		$ 0		$ 0		$ 0
Repurchase of Class C Common Stock				0		(307,000)
Repurchase of Class C Common Stock		(9,088)		$ 0		$ (307)		0		0		(8,781)		0
Stock-based compensation cost	1,788		0		0		1,788		0		0		0
Other stock-based award activity	(1,794)		0		0		(1,794)		0		0		0
Redemption of interest in subsidiary	53		$ 0		$ 0		0		0		0		53
Ending Balance (Shares Outstanding) at Jun. 30, 2016			8,400,000		10,460,000
Ending Balance at Jun. 30, 2016	585,153		$ 204,759		$ 10,460		117,989		12,384		239,349		212
Beginning Balance (Shares Outstanding) at Dec. 31, 2016			8,400,000		10,539,000
Beginning Balance at Dec. 31, 2016	643,647		$ 204,759		$ 10,539		118,655		33,758		275,714		222
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Attributable to Farmer Mac	42,694		0		0		0		0		42,694		0
Less: Net loss attributable to non-controlling interest	165		0		0		0		0		0		(165)
Other comprehensive income, net of tax	8,670		0		0		0		8,670		0		0
Preferred stock	(6,591)		0		0		0		0		(6,591)		0
Common stock	(7,616)		0		0		0		0		(7,616)		0
Stock Issued During Period, Shares, New Issues				0		65,000
Stock Issued During Period, Value, New Issues		$ 290		$ 0		$ 65		$ 225		$ 0		$ 0		$ 0
Repurchase of Class C Common Stock		(668,000)
Stock-based compensation cost	1,784		0		0		1,784		0		0		0
Other stock-based award activity	(1,727)		0		0		(1,727)		0		0		0
Redemption of interest in subsidiary	(57)		$ 0		$ 0		0		0		0		(57)
Ending Balance (Shares Outstanding) at Jun. 30, 2017			8,400,000		10,604,000
Ending Balance at Jun. 30, 2017	$ 680,929		$ 204,759		$ 10,604		$ 118,937		$ 42,428		$ 304,201		$ 0