Loans and Allowance for Losses and Concentrations of Credit Risk - Impaired Financing Receivables (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2016		Jun. 30, 2015	Jun. 30, 2016		Jun. 30, 2015	Dec. 31, 2015
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	$ 19,444			$ 19,444			$ 23,607
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	19,328			19,328			23,562
Impaired Financing Receivable, with Related Allowance, Recorded Investment	55,303	[1]		55,303	[1]		52,115	[2]
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	54,807			54,807			52,133
Impaired Financing Receivable, Recorded Investment	74,747			74,747			75,722
Impaired Financing Receivable, Unpaid Principal Balance	74,135			74,135			75,695
Impaired Financing Receivable, Related Allowance	2,345			2,345			1,850
Financing Receivable, Recorded Investment, Nonaccrual Status	32,552	[3]		32,552	[3]		41,672	[4]
Impaired Financing Receivable, Average Recorded Investment	76,520		$ 98,660	86,179		$ 93,794
Impaired Financing Receivable, Interest Income, Cash Basis Method	807		341	940		912
Crops [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	2,101			2,101			3,772
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	2,027			2,027			3,720
Impaired Financing Receivable, with Related Allowance, Recorded Investment	27,126	[1]		27,126	[1]		15,103	[2]
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	26,681			26,681			15,020
Impaired Financing Receivable, Recorded Investment	29,227			29,227			18,875
Impaired Financing Receivable, Unpaid Principal Balance	28,708			28,708			18,740
Impaired Financing Receivable, Related Allowance	721			721			476
Financing Receivable, Recorded Investment, Nonaccrual Status	8,629	[3]		8,629	[3]		5,105	[4]
Impaired Financing Receivable, Average Recorded Investment	28,732		24,392	26,121		21,471
Impaired Financing Receivable, Interest Income, Cash Basis Method	60		58	62		340
Permanent Plantings [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	13,840			13,840			12,340
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	13,804			13,804			12,346
Impaired Financing Receivable, with Related Allowance, Recorded Investment	11,409	[1]		11,409	[1]		11,939	[2]
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	11,320			11,320			11,938
Impaired Financing Receivable, Recorded Investment	25,249			25,249			24,279
Impaired Financing Receivable, Unpaid Principal Balance	25,124			25,124			24,284
Impaired Financing Receivable, Related Allowance	504			504			360
Financing Receivable, Recorded Investment, Nonaccrual Status	14,903	[3]		14,903	[3]		16,546	[4]
Impaired Financing Receivable, Average Recorded Investment	24,133		42,347	29,673		41,407
Impaired Financing Receivable, Interest Income, Cash Basis Method	509		142	553		225
Livestock [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	1,832			1,832			5,644
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	1,832			1,832			5,645
Impaired Financing Receivable, with Related Allowance, Recorded Investment	9,992	[1]		9,992	[1]		9,050	[2]
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	10,053			10,053			9,153
Impaired Financing Receivable, Recorded Investment	11,824			11,824			14,694
Impaired Financing Receivable, Unpaid Principal Balance	11,885			11,885			14,798
Impaired Financing Receivable, Related Allowance	894			894			787
Financing Receivable, Recorded Investment, Nonaccrual Status	3,329	[3]		3,329	[3]		4,313	[4]
Impaired Financing Receivable, Average Recorded Investment	14,883		14,247	13,906		14,683
Impaired Financing Receivable, Interest Income, Cash Basis Method	133		49	148		197
Part-Time Farm [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	1,671			1,671			1,851
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	1,665			1,665			1,851
Impaired Financing Receivable, with Related Allowance, Recorded Investment	6,776	[1]		6,776	[1]		6,185	[2]
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	6,753			6,753			6,184
Impaired Financing Receivable, Recorded Investment	8,447			8,447			8,036
Impaired Financing Receivable, Unpaid Principal Balance	8,418			8,418			8,035
Impaired Financing Receivable, Related Allowance	226			226			227
Financing Receivable, Recorded Investment, Nonaccrual Status	5,691	[3]		5,691	[3]		5,870	[4]
Impaired Financing Receivable, Average Recorded Investment	8,772		10,924	9,111		11,733
Impaired Financing Receivable, Interest Income, Cash Basis Method	105		92	177		150
Agriculture Storage and Processing [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	0			0			0
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	0			0			0
Impaired Financing Receivable, with Related Allowance, Recorded Investment	0	[1]		0	[1]		9,838	[2]
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	0			0			9,838
Impaired Financing Receivable, Recorded Investment	0			0			9,838
Impaired Financing Receivable, Unpaid Principal Balance	0			0			9,838
Impaired Financing Receivable, Related Allowance	0			0			0
Financing Receivable, Recorded Investment, Nonaccrual Status	0	[3]		0	[3]		9,838	[4]
Impaired Financing Receivable, Average Recorded Investment	0		6,750	7,368		4,500
Impaired Financing Receivable, Interest Income, Cash Basis Method	0		0	0		0
Other Commodity [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	0			0			0
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	0			0			0
Impaired Financing Receivable, with Related Allowance, Recorded Investment	0	[1]		0	[1]		0	[2]
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	0			0			0
Impaired Financing Receivable, Recorded Investment	0			0			0
Impaired Financing Receivable, Unpaid Principal Balance	0			0			0
Impaired Financing Receivable, Related Allowance	0			0			0
Financing Receivable, Recorded Investment, Nonaccrual Status	0	[3]		0	[3]		0	[4]
Impaired Financing Receivable, Average Recorded Investment	0		0	0		0
Impaired Financing Receivable, Interest Income, Cash Basis Method	0		$ 0	0		$ 0
Collateral Dependent Not Individually Analyzed [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	52,100			52,100			46,400
Impaired Financing Receivable, Related Allowance	$ 1,300			$ 1,300			$ 1,000
Impaired Financing Receivable, Impairment analysis performed percent	70.00%			70.00%			61.00%
Less than 90 days past due [Member]
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	$ 17,400	[3]		$ 17,400	[3]		$ 14,700	[4]

[1] Impairment analysis was performed in the aggregate in consideration of similar risk characteristics of the assets and historical statistics on $52.1 million (70 percent) of impaired loans as of June 30, 2016, which resulted in a specific reserve of $1.3 million.

[2] Impairment analysis was performed in the aggregate in consideration of similar risk characteristics of the assets and historical statistics on $46.4 million (61 percent) of impaired loans as of December 31, 2015, which resulted in a specific reserve of $1.0 million.

[3] Includes $17.4 million of loans that are less than 90 days delinquent but which have not met Farmer Mac's performance criteria for returning to accrual status.

[4] Includes $14.7 million of loans that are less than 90 days delinquent but which have not met Farmer Mac's performance criteria for returning to accrual status.