XML 27 R57.htm IDEA: XBRL DOCUMENT v2.4.0.6
Convertible Debt (Details) (USD $)
12 Months Ended
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Feb. 29, 2008
Debt Instrument [Line Items]        
Repurchase of convertible notes $ (10,081,000) $ (4,875,000) $ 0  
Convertible Senior Notes, Total 34,900,000 45,000,000    
Convertible senior notes 18,000,000 45,000,000    
Convertible senior notes, current 16,919,000 0    
Convertible Senior Notes [Member]
       
Debt Instrument [Line Items]        
Debt Instrument, Fair Value Disclosure 34,300,000 41,800,000    
Convertible Senior Notes [Member] | 2013 Convertible Senior Notes [Member]
       
Debt Instrument [Line Items]        
Debt Instrument, Face Amount       55,000,000
Debt Instrument, Interest Rate, Stated Percentage       2.75%
Effective interest rate 3.73% 3.64% 3.64%  
Contractually stated interest costs 1,289,000 1,372,000 1,375,000  
Amortization of interest costs 398,000 501,000 447,000  
Convertible Senior Notes [Member] | 2015 Convertible Senior Notes [Member]
       
Debt Instrument [Line Items]        
Debt Instrument, Convertible, Conversion Ratio 117.2333      
Debt Instrument, Convertible, Conversion Ratio, Principal Amount $ 1,000      
Debt Instrument, Convertible, Conversion Price $ 8.50      
Debt Instrument, Call Feature, Call Price, Percent of Principal 100.00%      
Effective interest rate 4500.00%