Mortgage-Backed Securities Narrative Tagging (Details) (USD $)	3 Months Ended						3 Months Ended										3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2013 Effective rate - minimum [Member]	Dec. 31, 2012 Effective rate - minimum [Member]	Mar. 31, 2013 Effective rate - maximum [Member]	Dec. 31, 2012 Effective rate - maximum [Member]	Dec. 31, 2012 Trust Portfolio--MBS Bonds [Member] Integer	Jun. 30, 2013 Trust Portfolio--MBS Bonds [Member]	Mar. 31, 2013 Trust Portfolio--MBS Bonds [Member]	Mar. 31, 2013 Trust Portfolio--MBS Bonds [Member] Effective rate - minimum [Member]	Mar. 31, 2013 Trust Portfolio--MBS Bonds [Member] Effective rate - maximum [Member]	Mar. 31, 2013 10% adverse [Member] Effective rate - minimum [Member]	Mar. 31, 2013 10% adverse [Member] Effective rate - maximum [Member]	Mar. 31, 2013 10% adverse [Member] Trust Portfolio--MBS Bonds [Member]	Mar. 31, 2013 10% adverse [Member] Trust Portfolio--MBS Bonds [Member] Effective rate - minimum [Member]	Mar. 31, 2013 10% adverse [Member] Trust Portfolio--MBS Bonds [Member] Effective rate - maximum [Member]	Jun. 30, 2012 LIFERS [Member]	Jun. 30, 2013 LIFERS [Member] Trust Portfolio--MBS Bonds [Member]	Mar. 31, 2013 LIFERS [Member] Trust Portfolio--MBS Bonds [Member]	Dec. 31, 2012 LIFERS [Member] Trust Portfolio--MBS Bonds [Member]	Jun. 30, 2013 SPEARS [Member] Trust Portfolio--MBS Bonds [Member]	Mar. 31, 2013 SPEARS [Member] Trust Portfolio--MBS Bonds [Member]	Dec. 31, 2012 SPEARS [Member] Trust Portfolio--MBS Bonds [Member]
Available-for-Sale Securities, Ownership Percentage	100.00%						100.00%										100.00%
Tolerable Range of Difference in Valuation	0.00%
Effective rate			5.50%	5.70%	8.30%	8.40%				3.60%	5.40%	6.00%	9.10%		4.00%	5.90%
Adverse change rate	10.00%								10.00%
Available-for-sale Securities, Gross Unrealized Losses	$ 4,180,745	$ 4,289,886					$ (413,665)		$ (516,571)					$ 2,600,000
Number of Available for Sale Securities, Mortgage Backed Securities							5
Available for Sale Securities, not Including Premiums							31,600,000	10,000,000	33,665,000									2,200,000			7,800,000
TOB Financing									$ 2,500,000										$ 500,000	$ 6,500,000		$ 26,700,000	$ 24,700,000