Quarterly report pursuant to Section 13 or 15(d)

Senior, Senior Subordinated, Convertible Senior Notes (Details Textual)

v2.4.0.6
Senior, Senior Subordinated, Convertible Senior Notes (Details Textual) (USD $)
3 Months Ended 3 Months Ended
Jun. 30, 2013
Mar. 31, 2013
Mar. 31, 2012
Mar. 31, 2013
7.731% senior subordinated notes due 2017 [Member]
Mar. 13, 2013
7.731% senior subordinated notes due 2017 [Member]
Dec. 31, 2012
7.731% senior subordinated notes due 2017 [Member]
Mar. 31, 2013
4.50% senior notes due two thousand eighteen [Member]
Mar. 31, 2013
7.00% senior notes due 2022 [Member]
Dec. 31, 2012
7.00% senior notes due 2022 [Member]
Mar. 31, 2013
7.15% senior notes due 2020 [Member]
Dec. 31, 2012
7.15% senior notes due 2020 [Member]
Mar. 31, 2013
1.875% convertible senior notes due 2032 [Member]
Dec. 31, 2012
1.875% convertible senior notes due 2032 [Member]
Mar. 31, 2013
Revolving Credit Facility [Member]
Dec. 31, 2012
Revolving Credit Facility [Member]
Dec. 31, 2012
Consolidated EBITDA [Member]
Revolving Credit Facility [Member]
Dec. 31, 2012
Consolidated Interest Incurred [Member]
Revolving Credit Facility [Member]
Debt Instrument [Line Items]                                  
Line of credit facility, maximum borrowing capacity   $ 60,000,000                              
Minimum net worth required for compliance                             360,000,000    
Leverage ratio                             60.00%    
Interest coverage ratio                               1.50 1.00
Line of credit facility, amount outstanding   0                       0 0    
Debt instrument, stated rate       7.731%     4.50% 7.00%   7.15%   1.875%          
Percentage of wholly owned subsidiary   100.00%                              
Senior notes unamortized discount                   3,406,000 3,528,000            
Year in which senior and senior subordinated notes due       2017   2017 2018 2022 2022 2020 2020 2032 2032        
Aggregate principal amount of offering           99,825,000 175,000,000                    
Aggregate principal amount repurchased         16,700,000                        
Debt instrument, convertible, conversion ratio                       17.1985          
Conversion principal amount                       1,000          
Senior and Senior Subordinated Notes (Textual) [Abstract]                                  
Loss on extinguishment of debt $ (3,000,000) $ 700,000 $ 0