Fair Value Disclosures - Fair Value Measurements, Recurring and Nonrecurring (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	$ 4,627	$ 3,816
Derivative Liability	34,064	39,213
Loans and Leases Receivable, Net Amount	4,334,434	3,962,044
Real estate owned, at lower of cost or fair value	1,528	1,369
Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	4,627	3,816
Assets, Fair Value Disclosure	9,947,109	8,849,256
Derivative Liability	123,796	77,199
Financial and Nonfinancial Liabilities, Fair Value Disclosure	123,796	77,199
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	0	19
Assets, Fair Value Disclosure	1,179,606	992,807
Derivative Liability	49	0
Financial and Nonfinancial Liabilities, Fair Value Disclosure	49	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	4,627	3,797
Assets, Fair Value Disclosure	1,808,624	1,741,110
Derivative Liability	123,747	77,199
Financial and Nonfinancial Liabilities, Fair Value Disclosure	123,747	77,199
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	0	0
Assets, Fair Value Disclosure	6,958,879	6,115,339
Derivative Liability	0	0
Financial and Nonfinancial Liabilities, Fair Value Disclosure	0	0
Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	1,583	11,831
Loans and Leases Receivable, Net Amount	1,234	11,443
Real estate owned, at lower of cost or fair value	349	388
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	0	0
Loans and Leases Receivable, Net Amount	0	0
Real estate owned, at lower of cost or fair value	0	0
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	0	0
Loans and Leases Receivable, Net Amount	0	0
Real estate owned, at lower of cost or fair value	0	0
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	1,583	11,831
Loans and Leases Receivable, Net Amount	1,234	11,443
Real estate owned, at lower of cost or fair value	349	388
Farmer Mac Guaranteed Securities [Member] | Available-for-sale Securities [Member] | Institutional Credit [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	4,904,657	4,121,244
Farmer Mac Guaranteed Securities [Member] | Available-for-sale Securities [Member] | Institutional Credit [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	0	0
Farmer Mac Guaranteed Securities [Member] | Available-for-sale Securities [Member] | Institutional Credit [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	0	0
Farmer Mac Guaranteed Securities [Member] | Available-for-sale Securities [Member] | Institutional Credit [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	4,904,657	4,121,244
Farmer Mac Guaranteed Securities [Member] | Available-for-sale Securities [Member] | USDA Guarantees [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	32,824	31,361
Farmer Mac Guaranteed Securities [Member] | Available-for-sale Securities [Member] | USDA Guarantees [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	0	0
Farmer Mac Guaranteed Securities [Member] | Available-for-sale Securities [Member] | USDA Guarantees [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	0	0
Farmer Mac Guaranteed Securities [Member] | Available-for-sale Securities [Member] | USDA Guarantees [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	32,824	31,361
Farmer Mac Guaranteed Securities and USDA Securities [Member] | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	4,937,481	4,152,605
Farmer Mac Guaranteed Securities and USDA Securities [Member] | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	0	0
Farmer Mac Guaranteed Securities and USDA Securities [Member] | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	0	0
Farmer Mac Guaranteed Securities and USDA Securities [Member] | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	4,937,481	4,152,605
Investment Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure		2,775,516
Investment Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure		992,788
Investment Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure		1,737,313
Investment Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure		45,415
Investment Securities [Member] | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	3,001,185	2,775,025
Investment Securities [Member] | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	1,179,606	992,788
Investment Securities [Member] | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	1,803,997	1,737,313
Investment Securities [Member] | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	17,582	44,924
Investment Securities [Member] | Trading Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure		491
Investment Securities [Member] | Trading Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure		0
Investment Securities [Member] | Trading Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure		0
Investment Securities [Member] | Trading Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure		491
USDA Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	2,003,816	1,917,319
USDA Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	0	0
USDA Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	0	0
USDA Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	2,003,816	1,917,319
USDA Securities [Member] | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	1,980,327	1,888,344
USDA Securities [Member] | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	0	0
USDA Securities [Member] | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	0	0
USDA Securities [Member] | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	1,980,327	1,888,344
USDA Securities [Member] | Trading Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	23,489	28,975
USDA Securities [Member] | Trading Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	0	0
USDA Securities [Member] | Trading Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	0	0
USDA Securities [Member] | Trading Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	23,489	28,975
Floating Interest Rate [Member] | Floating rate auction-rate certificates backed by Government guaranteed student loans | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	17,582	44,924
Floating Interest Rate [Member] | Floating rate auction-rate certificates backed by Government guaranteed student loans | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	0	0
Floating Interest Rate [Member] | Floating rate auction-rate certificates backed by Government guaranteed student loans | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	0	0
Floating Interest Rate [Member] | Floating rate auction-rate certificates backed by Government guaranteed student loans | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	17,582	44,924
Floating Interest Rate [Member] | Asset-backed Securities [Member] | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	51,654	73,729
Floating Interest Rate [Member] | Asset-backed Securities [Member] | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	0	0
Floating Interest Rate [Member] | Asset-backed Securities [Member] | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	51,654	73,729
Floating Interest Rate [Member] | Asset-backed Securities [Member] | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	0	0
Floating Interest Rate [Member] | Asset-backed Securities [Member] | Trading Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure		491
Floating Interest Rate [Member] | Asset-backed Securities [Member] | Trading Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure		0
Floating Interest Rate [Member] | Asset-backed Securities [Member] | Trading Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure		0
Floating Interest Rate [Member] | Asset-backed Securities [Member] | Trading Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure		491
Floating Interest Rate [Member] | Corporate Debt Securities [Member] | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	15,019	9,991
Floating Interest Rate [Member] | Corporate Debt Securities [Member] | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	0	0
Floating Interest Rate [Member] | Corporate Debt Securities [Member] | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	15,019	9,991
Floating Interest Rate [Member] | Corporate Debt Securities [Member] | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	0	0
Floating Interest Rate [Member] | Government/GSE Guaranteed Mortgage Backed Securities [Member] | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	1,300,691	1,355,459
Floating Interest Rate [Member] | Government/GSE Guaranteed Mortgage Backed Securities [Member] | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	0	0
Floating Interest Rate [Member] | Government/GSE Guaranteed Mortgage Backed Securities [Member] | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	1,300,691	1,355,459
Floating Interest Rate [Member] | Government/GSE Guaranteed Mortgage Backed Securities [Member] | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	0	0
Floating Interest Rate [Member] | GSE Subordinated Debt [Member} | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	66,404	66,249
Floating Interest Rate [Member] | GSE Subordinated Debt [Member} | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	0	0
Floating Interest Rate [Member] | GSE Subordinated Debt [Member} | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	66,404	66,249
Floating Interest Rate [Member] | GSE Subordinated Debt [Member} | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	0	0
Floating Interest Rate [Member] | Senior Agency Debt [Member] | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	362,523	213,987
Floating Interest Rate [Member] | Senior Agency Debt [Member] | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	0	0
Floating Interest Rate [Member] | Senior Agency Debt [Member] | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	362,523	213,987
Floating Interest Rate [Member] | Senior Agency Debt [Member] | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	0	0
Fixed Interest Rate [Member] | Corporate Debt Securities [Member] | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure		9,994
Fixed Interest Rate [Member] | Corporate Debt Securities [Member] | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure		0
Fixed Interest Rate [Member] | Corporate Debt Securities [Member] | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure		9,994
Fixed Interest Rate [Member] | Corporate Debt Securities [Member] | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure		0
Fixed Interest Rate [Member] | Government/GSE Guaranteed Mortgage Backed Securities [Member] | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	7,706	7,904
Fixed Interest Rate [Member] | Government/GSE Guaranteed Mortgage Backed Securities [Member] | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	0	0
Fixed Interest Rate [Member] | Government/GSE Guaranteed Mortgage Backed Securities [Member] | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	7,706	7,904
Fixed Interest Rate [Member] | Government/GSE Guaranteed Mortgage Backed Securities [Member] | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	0	0
Fixed Interest Rate [Member] | US Treasury Securities [Member] | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	1,179,606	992,788
Fixed Interest Rate [Member] | US Treasury Securities [Member] | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	1,179,606	992,788
Fixed Interest Rate [Member] | US Treasury Securities [Member] | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	0	0
Fixed Interest Rate [Member] | US Treasury Securities [Member] | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	$ 0	$ 0