Fair Value Measurements (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Schedule of assets and liabilities measured at fair value on recurring basis
Interest Rate Derivative Liabilities, at Fair Value Disclosure	$ 249	$ 238
Fair Value, Inputs, Level 1
Schedule of assets and liabilities measured at fair value on recurring basis
Interest Rate Derivative Liabilities, at Fair Value Disclosure	0	0
Fair Value, Inputs, Level 2
Schedule of assets and liabilities measured at fair value on recurring basis
Interest Rate Derivative Liabilities, at Fair Value Disclosure	249	238
Fair Value, Inputs, Level 3
Schedule of assets and liabilities measured at fair value on recurring basis
Interest Rate Derivative Liabilities, at Fair Value Disclosure	0	0
Money market mutual funds [Member]
Schedule of assets and liabilities measured at fair value on recurring basis
Assets, Fair Value Disclosure	17,061	13,244
Money market mutual funds [Member] | Fair Value, Inputs, Level 1
Schedule of assets and liabilities measured at fair value on recurring basis
Assets, Fair Value Disclosure	17,061	13,244
Money market mutual funds [Member] | Fair Value, Inputs, Level 2
Schedule of assets and liabilities measured at fair value on recurring basis
Assets, Fair Value Disclosure	0	0
Money market mutual funds [Member] | Fair Value, Inputs, Level 3
Schedule of assets and liabilities measured at fair value on recurring basis
Assets, Fair Value Disclosure	0	0
US Treasury Securities
Schedule of assets and liabilities measured at fair value on recurring basis
Assets, Fair Value Disclosure		1,002
US Treasury Securities | Fair Value, Inputs, Level 1
Schedule of assets and liabilities measured at fair value on recurring basis
Assets, Fair Value Disclosure		1,002
US Treasury Securities | Fair Value, Inputs, Level 2
Schedule of assets and liabilities measured at fair value on recurring basis
Assets, Fair Value Disclosure		0
US Treasury Securities | Fair Value, Inputs, Level 3
Schedule of assets and liabilities measured at fair value on recurring basis
Assets, Fair Value Disclosure		0
Corporate notes [Member]
Schedule of assets and liabilities measured at fair value on recurring basis
Assets, Fair Value Disclosure		2,284
Corporate notes [Member] | Fair Value, Inputs, Level 1
Schedule of assets and liabilities measured at fair value on recurring basis
Assets, Fair Value Disclosure		0
Corporate notes [Member] | Fair Value, Inputs, Level 2
Schedule of assets and liabilities measured at fair value on recurring basis
Assets, Fair Value Disclosure		2,284
Corporate notes [Member] | Fair Value, Inputs, Level 3
Schedule of assets and liabilities measured at fair value on recurring basis
Assets, Fair Value Disclosure		0
Certificates of Deposit
Schedule of assets and liabilities measured at fair value on recurring basis
Assets, Fair Value Disclosure	5,598	6,089
Certificates of Deposit | Fair Value, Inputs, Level 1
Schedule of assets and liabilities measured at fair value on recurring basis
Assets, Fair Value Disclosure	5,598	6,089
Certificates of Deposit | Fair Value, Inputs, Level 2
Schedule of assets and liabilities measured at fair value on recurring basis
Assets, Fair Value Disclosure	0	0
Certificates of Deposit | Fair Value, Inputs, Level 3
Schedule of assets and liabilities measured at fair value on recurring basis
Assets, Fair Value Disclosure	$ 0	$ 0