Annual report pursuant to Section 13 and 15(d)

Debt - Textual (Details)

v3.3.1.900
Debt - Textual (Details)
1 Months Ended 12 Months Ended
Apr. 01, 2015
d
$ / shares
Aug. 30, 2013
USD ($)
Aug. 30, 2013
USD ($)
Aug. 30, 2013
USD ($)
shares
Aug. 30, 2013
USD ($)
conversion_right
Aug. 30, 2013
USD ($)
Rate
Jun. 30, 2014
USD ($)
shares
Jan. 31, 2013
USD ($)
$ / shares
Jan. 31, 2013
USD ($)
$ / shares
Jan. 31, 2013
USD ($)
$ / shares
Rate
Dec. 31, 2015
USD ($)
Dec. 31, 2015
USD ($)
Dec. 31, 2015
USD ($)
shares
Dec. 31, 2015
USD ($)
Rate
Nov. 05, 2015
USD ($)
Jan. 30, 2013
USD ($)
Notes | Notes Due February 1, 2033                                
Debt Instrument [Line Items]                                
Debt face amount                               $ 175,000,000.0
Interest rate of notes payable                               3.00%
Equivalent redemption price                 100.00%              
Conversion rate     141.48     14148.00%     141.4827 14148.27%   141.4827   14148.27%    
Conversion principal amount   $ 1,000 $ 1,000 $ 1,000 $ 1,000 $ 1,000   $ 1,000 $ 1,000 $ 1,000 $ 1,000 $ 1,000 $ 1,000 $ 1,000    
Conversion price | $ / shares $ 7.07             $ 7.07 $ 7.07 $ 7.07            
Convertible debt, threshold percentage of stock price trigger 130.00%               130.00%              
Number of consecutive trading days applicable conversion price 30 days                              
Conversion rights triggered | conversion_right         1                      
Convertible notes, conversion   16,900,000                 55,400,000          
Convertible debt, stock issued from conversion | shares       2,396,145                 8,118,062      
Gain on conversion   $ 1,000,000                            
Converted amount             $ 70,400,000                  
Interest paid             800,000                  
Gains (losses) on extinguishment of debt             $ 2,700,000       $ 900,000          
Common stock trigger price | $ / shares $ 9.19                              
Threshold trading days | d 20                              
Notes | Notes Due February 1, 2033 | On or After February 1, 2017 and before February 1, 2019                                
Debt Instrument [Line Items]                                
Equivalent redemption price                 100.00%              
Minimum | Notes | Notes Due February 1, 2033                                
Debt Instrument [Line Items]                                
Number of trading days               20 days                
Maximum | Notes | Notes Due February 1, 2033                                
Debt Instrument [Line Items]                                
Number of consecutive trading days applicable conversion price               30 days                
Common Stock | Notes | Notes Due February 1, 2033                                
Debt Instrument [Line Items]                                
Convertible debt, stock issued from conversion | shares             10,974,431                  
Revolving Credit Facility | Line of Credit | New Credit Agreement                                
Debt Instrument [Line Items]                                
Credit line capacity                             $ 175,000,000.0  
Bridge Loan | Line of Credit | New Credit Agreement                                
Debt Instrument [Line Items]                                
Credit line capacity                             20,000,000.0  
Letter of Credit | Line of Credit | New Credit Agreement                                
Debt Instrument [Line Items]                                
Credit line capacity                             $ 20,000,000.0