Financial Instruments (Details) - USD ($) $ in Thousands		3 Months Ended		12 Months Ended
		Mar. 31, 2016	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Level 3 financial liabilities ending balance			$ 318		$ 318	$ 968
Fair value of asset measured on a recurring basis
Fixed income available-for-sale securities			16,978	$ 11,983	16,978
Business Combination, Contingent Consideration, Liability			318		318
Adjustment to contingent consideration		$ (318)	(577)	(318)	(650)	$ 43
Decrease in contingent consideration liability due to performance targets				(759)
Amortization of contingent consideration				109
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair value of asset measured on a recurring basis
Money market funds	[1]		2,305	4,513	2,305
Fixed income available-for-sale securities	[2]		0	0	0
Business Combination, Contingent Consideration, Liability			0		0
Liabilities, Fair Value Disclosure, Recurring			0		0
Assets, Fair Value Disclosure, Recurring			2,305	4,513	2,305
Significant Other Observable Inputs (Level 2) [Member]
Fair value of asset measured on a recurring basis
Money market funds	[1]		0	0	0
Fixed income available-for-sale securities	[2]		18,379	13,233	18,379
Business Combination, Contingent Consideration, Liability			0		0
Liabilities, Fair Value Disclosure, Recurring			0		0
Assets, Fair Value Disclosure, Recurring			18,379	13,233	18,379
Significant Unobservable Inputs (Level 3) [Member]
Fair value of asset measured on a recurring basis
Money market funds	[1]		0	0	0
Fixed income available-for-sale securities	[2]		0	0	0
Business Combination, Contingent Consideration, Liability			318		318
Liabilities, Fair Value Disclosure, Recurring			318		318
Assets, Fair Value Disclosure, Recurring			0	0	0
Fair Value, Measurements, Recurring [Member]
Fair value of asset measured on a recurring basis
Money market funds	[1]		2,305	4,513	2,305
Fixed income available-for-sale securities	[2]		18,379	13,233	18,379
Liabilities, Fair Value Disclosure, Recurring			318		318
Assets, Fair Value Disclosure, Recurring			$ 20,684	$ 17,746	$ 20,684

[1] Included in cash and cash equivalents in the Company’s consolidated balance sheets

[2] Represents the portfolio of available-for-sale securities and is included in restricted investments and short-term investments in the Company’s consolidated balance sheets