Debt (Details Textual) (USD $)	6 Months Ended			3 Months Ended	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014 2012 Credit Agreement Revolving Loan	Mar. 31, 2014 2010 Convertible Notes	Jun. 30, 2014 2010 Convertible Notes
Debt Disclosure [Abstract]
Cash used for repayment of debt	$ 7,500,000	$ 7,500,000
Amount available under revolving loan facility			100,000,000
Conversion obligation settlement in cash					100.00%
Initial conversion rate of common stock				41.8811	42.1363
Convertible Notes, initial conversion of Par Value Convertible Notes to common stock				$ 1,000	$ 1,000
Initial conversion price				$ 23.88	$ 23.73
Common stock price trigger				$ 31.04	$ 30.85
Rate of conversion price				130.00%	130.00%