XML 147 R61.htm IDEA: XBRL DOCUMENT v3.19.1
Debt (Senior Notes) (Narrative) (Details) - USD ($)
$ in Thousands
1 Months Ended 12 Months Ended
Jan. 31, 2017
Jan. 31, 2019
Jan. 31, 2018
Jan. 31, 2017
Feb. 27, 2017
Debt Instrument          
Payments of Debt Issuance Costs   $ 0 $ 6,348 $ 21,581  
Senior Notes | 4.95% Senior Notes          
Debt Instrument          
Debt Instrument, Redemption Price, Discounted Scheduled Payments, Discount Rate, Basis Spread on Variable Rate   0.40%      
Debt Instrument, Maturity Date Feb. 15, 2027        
Debt Instrument, Face Amount $ 500,000 $ 500,000 500,000 $ 500,000  
Debt Instrument, Interest Rate, Stated Percentage 4.95%     4.95%  
Debt Instrument, Redemption Price, Percentage 100.00%        
Senior Notes | 3.70% Senior Notes          
Debt Instrument          
Debt Instrument, Redemption Price, Discounted Scheduled Payments, Discount Rate, Basis Spread on Variable Rate   0.30%      
Debt Instrument, Maturity Date Feb. 15, 2022        
Debt Instrument, Face Amount $ 500,000 $ 500,000 $ 500,000 $ 500,000  
Debt Instrument, Interest Rate, Stated Percentage 3.70%     3.70%  
Debt Instrument, Redemption Price, Percentage 100.00%        
Term loan credit agreement          
Debt Instrument          
Debt Instrument, Face Amount         $ 1,000,000
Term loan credit agreement | 3 year maturity          
Debt Instrument          
Debt Instrument, Face Amount         $ 250,000