Investment Securities Table (Details) $ in Thousands	Dec. 31, 2015 USD ($)
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities	$ 41,233
Federal tax-exempt debt securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities	4,951
Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities	25,400
US Treasury Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities	7,537
Commercial Paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities	2,097
Certificates of deposit [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities	$ 1,248