Investment in Securities (Details 1) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Estimated fair value less than 12 months	$ 19,758	$ 4,362
Unrealized losses less than 12 months	112	20
Estimated fair value 12 months or more	0	0
Unrealized losses 12 months or more	0	0
Estimated fair value total	19,758	4,362
Unrealized losses total	112	20
Us States and Political Subdivisions Debt Securities [Member]
Estimated fair value less than 12 months	19,758	4,362
Unrealized losses less than 12 months	112	20
Estimated fair value 12 months or more	0	0
Unrealized losses 12 months or more	0	0
Estimated fair value total	19,758	4,362
Unrealized losses total	112	20
Certificates Of Deposit [Member]
Estimated fair value less than 12 months	0	0
Unrealized losses less than 12 months	0	0
Estimated fair value 12 months or more	0	0
Unrealized losses 12 months or more	0	0
Estimated fair value total	0	0
Unrealized losses total	$ 0	$ 0