v3.3.1.900
Credit Facility (Details) - USD ($)
12 Months Ended
Feb. 09, 2016
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2011
CRLLC | Subsequent Event | Credit Facility Guaranty Agreement        
Credit Facility        
Face amount of third party debt $ 125,000,000      
Minimum | CRLLC | Subsequent Event | Credit Facility Guaranty Agreement        
Credit Facility        
Term of third party debt 1 year      
Maximum | CRLLC | Subsequent Event | Credit Facility Guaranty Agreement        
Credit Facility        
Term of debt 2 years      
CRNF Credit Facility        
Credit Facility        
Period of trailing quarters used in calculating the leverage ratio   12 months    
Effective rate (as a percent)   4.60%    
Lender and other third party costs incurred       $ 4,800,000
CRNF Credit Facility | Eurodollar        
Credit Facility        
Basis spread on variable rate (as a percent)   3.50%    
CRNF Credit Facility | Eurodollar | Minimum        
Credit Facility        
Basis spread on variable rate (as a percent)   3.50%    
CRNF Credit Facility | Eurodollar | Maximum        
Credit Facility        
Basis spread on variable rate (as a percent)   4.25%    
CRNF Credit Facility | Base Rate | Minimum        
Credit Facility        
Basis spread on variable rate (as a percent)   2.50%    
CRNF Credit Facility | Base Rate | Maximum        
Credit Facility        
Basis spread on variable rate (as a percent)   3.25%    
CRNF Credit Facility | Prime Rate        
Credit Facility        
Basis spread on variable rate (as a percent)   2.50%    
Line of Credit | CRNF Credit Facility        
Credit Facility        
Amount outstanding under revolving credit facility   $ 0 $ 0  
Term Loan | Line of Credit | CRNF Credit Facility        
Credit Facility        
Debt instrument face amount   125,000,000    
Revolving Credit Facility | Line of Credit | CRNF Credit Facility        
Credit Facility        
Borrowing capacity   25,000,000.0    
Uncommitted incremental facility   $ 50,000,000.0