Investments and Fair Value Measurements (Details) - Corporate Securities [Member] - Investments (Current) [Member] - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2016	Dec. 31, 2015
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity Securities, Amortized Cost	$ 1,100	$ 12,425
Held to -maturity Securities, Remaining Maturity
Minimum [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held to -maturity Securities, Remaining Maturity		15 days
Maximum [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held to -maturity Securities, Remaining Maturity		202 days