Investment in Securities (Schedule of the Fair Values of Securities with Unrealized Losses) (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Investment [Line Items]
Estimated fair value, less than 12 months	$ 2,503	$ 3,638
Estimated fair value, 12 months or more		1,208
Estimated fair value, total	2,503	4,846
Unrealized losses, less than 12 months		5
Unrealized losses, 12 months or more		8
Unrealized losses, total		13
State and Political Subdivisions [Member]
Investment [Line Items]
Estimated fair value, less than 12 months	2,503	3,638
Estimated fair value, 12 months or more		1,208
Estimated fair value, total	2,503	4,846
Unrealized losses, less than 12 months		5
Unrealized losses, 12 months or more		8
Unrealized losses, total		13
Certificates of Deposit [Member]
Investment [Line Items]
Estimated fair value, less than 12 months
Estimated fair value, 12 months or more
Estimated fair value, total
Unrealized losses, less than 12 months
Unrealized losses, 12 months or more
Unrealized losses, total