Liquidity (Details Textual) (USD $)	0 Months Ended
	Dec. 10, 2014	Mar. 31, 2015	Dec. 31, 2014		Mar. 31, 2014	Dec. 31, 2013	Dec. 16, 2014
Liquidity Details [Line Items]
Cash and Cash Equivalents, at Carrying Value		$ 157,031,000	$ 158,883,000	[1]	$ 2,414,000	$ 2,101,000
Line of Credit Facility, Remaining Borrowing Capacity		6,800,000
Line of Credit Facility, Maximum Borrowing Capacity		10,000,000
Debt Instrument, Interest Rate, Stated Percentage		3.75%	3.75%
Additional Aggregate Consideration For Purchased Assets		6,000,000
Convertible Notes Payable [Member]
Liquidity Details [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.75%	3.75%	3.75%				3.75%
Debt Issuance Cost	4,800,000
Proceeds from Issuance of Senior Long-term Debt	$ 139,000,000

[1] *Derived from the audited December 31, 2014 financial statements