Quarterly report pursuant to Section 13 or 15(d)

Debt (Narrative) (Details)

v3.5.0.2
Debt (Narrative) (Details)
$ / shares in Units, $ in Millions
3 Months Ended 9 Months Ended
Sep. 14, 2016
USD ($)
day
$ / shares
Sep. 24, 2016
USD ($)
Sep. 24, 2016
USD ($)
Sep. 26, 2015
USD ($)
Sep. 28, 2016
USD ($)
Sep. 23, 2016
$ / shares
Debt Instrument [Line Items]            
Share price (in usd per share) | $ / shares           $ 6.55
Gain (Loss) on Extinguishment of Debt     $ (61) $ 0    
Convertible Debt | 2.125% Convertible Senior Notes due 2026            
Debt Instrument [Line Items]            
Principal $ 700 $ 700 700      
Debt Instrument, Interest Rate, Stated Percentage 2.125%          
Debt Instrument, Convertible, Conversion Ratio 0.1250031          
Debt Instrument, Convertible, Conversion Price | $ / shares $ 8.00          
Debt Issuance Cost, Gross, Noncurrent   12 12      
Equity issuance costs   $ 8 $ 8      
Debt Instrument, Convertible, Remaining Life     120 months      
Debt Instrument, Interest Rate, Effective Percentage   8.00% 8.00%      
Convertible Debt | 2.125% Convertible Senior Notes due 2026 | Debt Instrument, Conversion Circumstance 1            
Debt Instrument [Line Items]            
Debt Instrument, Convertible, Threshold Trading Days | day 20          
Debt Instrument, Convertible, Threshold Consecutive Trading Days 30 days          
Debt Instrument, Convertible, Threshold Percentage of Stock Price Trigger 130.00%          
Convertible Debt | 2.125% Convertible Senior Notes due 2026 | Debt Instrument, Conversion Circumstance 2            
Debt Instrument [Line Items]            
Debt Instrument, Convertible, Threshold Consecutive Trading Days 10 days          
Debt Instrument, Convertible, Threshold Percentage of Stock Price Trigger 98.00%          
Debt Instrument, Convertible, Conversion Period After Threshold Period Days | day 5          
Convertible Debt | 2.125% Convertible Senior Notes Due 2026, Over-Allotment Option | Subsequent Event            
Debt Instrument [Line Items]            
Principal         $ 105  
Senior Notes | 6.75% Senior Notes due 2019            
Debt Instrument [Line Items]            
Debt Instrument, Interest Rate, Stated Percentage   6.75% 6.75%      
Debt Instrument, Repurchased Face Amount   $ 404 $ 404      
Early Repayment of Senior Debt   442        
Interest Paid   2        
Gain (Loss) on Extinguishment of Debt   (41)        
Outstanding Aggregate Principal Amount   $ 196 $ 196      
Senior Notes | 7.75% Senior Notes due 2020            
Debt Instrument [Line Items]            
Debt Instrument, Interest Rate, Stated Percentage   7.75% 7.75%      
Debt Instrument, Repurchased Face Amount   $ 242 $ 242      
Early Repayment of Senior Debt   251        
Interest Paid   3        
Gain (Loss) on Extinguishment of Debt   (9)        
Outstanding Aggregate Principal Amount   $ 208 $ 208      
Senior Notes | 7.75% Senior Notes due 2020 | Subsequent Event            
Debt Instrument [Line Items]            
Debt Instrument, Repurchased Face Amount         $ 208  
Senior Notes | 7.50% Senior Notes due 2022            
Debt Instrument [Line Items]            
Debt Instrument, Interest Rate, Stated Percentage   7.50% 7.50%      
Debt Instrument, Repurchased Face Amount   $ 125 $ 125      
Early Repayment of Senior Debt   135        
Interest Paid   1        
Gain (Loss) on Extinguishment of Debt   (10)        
Outstanding Aggregate Principal Amount   $ 350 $ 350      
Senior Notes | 7.00% Senior Notes due 2024            
Debt Instrument [Line Items]            
Debt Instrument, Interest Rate, Stated Percentage   7.00% 7.00%      
Debt Instrument, Repurchased Face Amount   $ 25 $ 25      
Early Repayment of Senior Debt   26        
Interest Paid   1        
Gain (Loss) on Extinguishment of Debt   (1)        
Outstanding Aggregate Principal Amount   $ 475 $ 475