Available-for-Sale Securities (Details) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2016 USD ($) item	Jun. 30, 2016 USD ($) item
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost Basis	$ 18,531	$ 18,531
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	8	8
Fair Value	$ 18,539	$ 18,539
Number of available-for-sale securities in an unrealized loss position | item	2	2
Unrealized loss position, available-for-sale securities	$ 1,500	$ 1,500
Proceeds from sales of available for sale securities	4,500	7,800
Corporate Debt Securities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost Basis	14,826	14,826
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	7	7
Fair Value	14,833	14,833
U.S. Government-sponsored Securities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost Basis	3,705	3,705
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	1	1
Fair Value	$ 3,706	$ 3,706