XML 64 R50.htm IDEA: XBRL DOCUMENT v3.3.1.900
Stock Plans and Share-Based Compensation (Long-term Incentive Plans) (Details)
$ / shares in Units, $ in Millions
12 Months Ended
Dec. 25, 2015
USD ($)
plan
$ / shares
shares
Dec. 26, 2014
USD ($)
Dec. 27, 2013
USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Total (benefit) expense | $ $ 12 $ 33 $ 14
Long-term Incentive Plans [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Percentage of payout subject to reduction (up to) 30.00%    
Total (benefit) expense | $ $ (1) $ 19 $ 2
Long-term Incentive Plans [Member] | Minimum [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Payout Range 0.00%    
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]      
Payout Range 0.00%    
Long-term Incentive Plans [Member] | Maximum [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Payout Range 200.00%    
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]      
Payout Range 200.00%    
Performance Units [Member] | Long-term Incentive Plans [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Performance unit equivalent of CSX stock, in shares 1    
Plan duration 3 years    
Number of plans | plan 3    
Payout percentage cumulative period 3 years    
Percentage payout on operating ratio 50.00%    
Percentage payout on average return on assets 50.00%    
Performance Units [Member] | Long Term Incentive Plan - 2014 [Member]      
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]      
Number of target units outstanding [1] 1,317,000    
Weighted-average fair value at grant date (dollars per share) | $ / shares [1] $ 25.90    
Performance Units [Member] | Long Term Incentive Plan - 2014 [Member] | Minimum [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Payout Range 0.00%    
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]      
Payout Range 0.00%    
Performance Units [Member] | Long Term Incentive Plan - 2014 [Member] | Maximum [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Payout Range 200.00%    
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]      
Payout Range 200.00%    
Performance Units [Member] | Long Term Incentive Plan - 2015 [Member]      
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]      
Number of target units outstanding [1] 1,115,000    
Weighted-average fair value at grant date (dollars per share) | $ / shares [1] $ 28.60    
Performance Units [Member] | Long Term Incentive Plan - 2015 [Member] | Minimum [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Payout Range 0.00%    
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]      
Payout Range 0.00%    
Performance Units [Member] | Long Term Incentive Plan - 2015 [Member] | Maximum [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Payout Range 200.00%    
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]      
Payout Range 200.00%    
Performance Units [Member] | Long Term Incentive Plan - 2016 [Member]      
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]      
Number of target units outstanding [1] 826,000    
Weighted-average fair value at grant date (dollars per share) | $ / shares [1] $ 35.94    
Performance Units [Member] | Long Term Incentive Plan - 2016 [Member] | Minimum [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Payout Range 0.00%    
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]      
Payout Range 0.00%    
Performance Units [Member] | Long Term Incentive Plan - 2016 [Member] | Maximum [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Payout Range 200.00%    
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]      
Payout Range 200.00%    
[1] Number of target units granted and weighted-average fair value calculations above include the value of both initial grants and subsequent, smaller grants issued at different prices based on grant date fair value to new or promoted employees not previously included.