Quarterly report pursuant to Section 13 or 15(d)

Debt and Secured Revolving Facility (Narrative) (Details)

v3.20.1
Debt and Secured Revolving Facility (Narrative) (Details)
1 Months Ended 3 Months Ended
Apr. 06, 2020
USD ($)
Jun. 07, 2019
USD ($)
Sep. 30, 2016
USD ($)
day
$ / shares
Mar. 28, 2020
USD ($)
$ / shares
Dec. 28, 2019
USD ($)
Aug. 15, 2012
USD ($)
2.125% Convertible Senior Notes due 2026            
Debt Instrument [Line Items]            
Stated interest rate     2.125% 2.125%    
Principal amount     $ 805,000,000 $ 251,000,000 $ 251,000,000  
Conversion price (in usd per share) | $ / shares     $ 8.00      
Share price (in usd per share) | $ / shares       $ 46.58    
If-converted value in excess of principal       $ 1,200,000,000    
Effective interest rate       8.00%    
2.125% Convertible Senior Notes due 2026 | Debt Instrument, circumstance 1            
Debt Instrument [Line Items]            
Threshold trading days | day     20      
Threshold consecutive trading days | day     30      
Threshold percentage of conversion price     130.00%      
7.50% Senior Notes due 2022            
Debt Instrument [Line Items]            
Stated interest rate       7.50%    
Principal amount           $ 500,000,000
Outstanding aggregate principal amount       $ 312,000,000    
Secured Revolving Credit Facility            
Debt Instrument [Line Items]            
Letters of credit outstanding, amount       14,000,000    
Secured Revolving Credit Facility | Secured Revolving Line of Credit            
Debt Instrument [Line Items]            
Maximum borrowing capacity   $ 500,000,000        
Debt instrument, term   5 years        
Amount of assets sales that must be reinvested within twelve month period   $ 250,000,000        
Long-term line of credit       $ 0    
Secured Revolving Credit Facility | Secured Revolving Line of Credit | Subsequent Event            
Debt Instrument [Line Items]            
Effective interest rate 2.37%          
Proceeds from lines of credit $ 200,000,000          
Secured Revolving Credit Facility | Swingline Subfacility            
Debt Instrument [Line Items]            
Maximum borrowing capacity   50,000,000        
Secured Revolving Credit Facility | Letter of Credit            
Debt Instrument [Line Items]            
Maximum borrowing capacity   $ 75,000,000