Mortgage Backed Securities Mortgage backed securities designated as Trading (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading Securities, Debt	$ 28,978		$ 28,978		$ 30,069
Trading Securities, Amortized cost	27,078		27,078		27,535
Unrealized Gain on Securities	96	283		716
Unrealized Loss on Securities			$ (634)