Annual report pursuant to Section 13 and 15(d)

Summary of Significant Accounting Policies (Notes) (Details)

v3.10.0.1
Summary of Significant Accounting Policies (Notes) (Details)
 1 Months Ended 12 Months Ended
Dec. 31, 2018
USD ($)
Nov. 30, 2018
USD ($)
Mar. 31, 2018
USD ($)
unit
Dec. 31, 2018
USD ($)
Dec. 31, 2017
USD ($)
Dec. 31, 2016
USD ($)
May 25, 2018
USD ($)
Dec. 15, 2014
USD ($)
Feb. 01, 2014
Convertible Notes                  
Interest rate (as a percent)               1.75%  
Face amount               $ 172,500,000  
Ownership interest (as a percent)   27.00% 43.00%            
Cash consideration       $ 0 $ 445,000 $ 0      
Net loss attributable to noncontrolling interest       (1,745,000) 0 0      
Investment in private companies   $ 1,200,000              
Convertible Notes                  
Convertible Notes                  
Face amount and over allotments               $ 172,500,000  
Interest rate (as a percent)               1.75%  
Face amount $ 172,500,000     172,500,000 172,500,000        
Convertible Notes Due 2023                  
Convertible Notes                  
Interest rate (as a percent)             1.75%    
Face amount 345,000,000     345,000,000 0   $ 345,000,000    
ERS                  
Convertible Notes                  
Ownership interest (as a percent)                 64.50%
Net loss attributable to noncontrolling interest       $ 0 $ 0 $ 0      
Private Company                  
Convertible Notes                  
Number of units acquired | unit     4,000            
Investment in private companies     $ 1,333,000            
Klein | ERS                  
Convertible Notes                  
Ownership interest (as a percent)           81.50%      
ERS                  
Convertible Notes                  
Cash consideration $ 6,560,000                
Percentage of interests acquired 100.00%     100.00%