Debt (Details Textual) (USD $)	9 Months Ended				9 Months Ended	12 Months Ended	9 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012	Sep. 30, 2013 Revolving Credit Facility	Sep. 30, 2013 2012 Credit Agreement	Dec. 31, 2012 2012 Credit Agreement	Sep. 30, 2013 2010 Convertible Notes	Dec. 31, 2012 2010 Convertible Notes	Sep. 30, 2013 2010 Convertible Notes Pre August Dividend	Sep. 30, 2013 2010 Convertible Notes Post August Dividend
Debt (Textual) [Abstract]
Term loan description					LIBOR plus 2.00%
Basis Spread on Term Loan					2.00%
Term Loan Combined Interest Rate					2.26%	2.31%
Maturity period					2017-11
2012 Credit Agreement Early Termination Date					Dec. 01, 2016
Amount available under revolving credit facility				$ 100,000,000
Shares of common stock prior conversion									41.1794	41.4371
In principal amount of convertible notes									1,000	1,000
Conversion price on 2010 Convertible Notes									$ 24.28	$ 24.13
Common stock price trigger									$ 31.56	$ 31.37
Rate of conversion price									130.00%	130.00%
Interest rate on senior subordinated convertible notes							3.00%
Long-term debt, unamortized original issue discount	21,327,000		25,302,000				21,327,000	25,302,000
Maturity date of 2010 Convertible Notes							Mar. 01, 2017
Payments on long-term debt	$ 11,250,000	$ 22,000,000			$ 11,250,000
Cash payable on conversion of 2010 Convertible Notes							100.00%