XML 131 R83.htm IDEA: XBRL DOCUMENT v3.10.0.1
Debt - Credit Facility (Details) - Credit Facility - USD ($)
12 Months Ended
Jan. 31, 2019
Dec. 31, 2018
May 31, 2018
Jan. 31, 2017
Revolving Credit Facility        
Line of Credit Facility [Line Items]        
Maximum borrowing capacity     $ 300,000,000 $ 500,000,000
Term of debt instrument   5 years    
Current borrowing capacity   $ 493,000,000    
Letter of Credit        
Line of Credit Facility [Line Items]        
Amount outstanding under Letter of Credit   $ 7,000,000    
Subsequent Event | Revolving Credit Facility        
Line of Credit Facility [Line Items]        
Maximum borrowing capacity $ 600,000,000      
Minimum threshold for advancements $ 50,000,000      
Delayed draw ticking fee 0.375%      
Subsequent Event | Minimum | Revolving Credit Facility        
Line of Credit Facility [Line Items]        
Amortization payment percentage 1.25%      
Subsequent Event | Maximum | Revolving Credit Facility        
Line of Credit Facility [Line Items]        
Amortization payment percentage 2.50%