v3.3.1.900
Equity-Based Compensation Information Related to Stock Options (Details) - USD ($)
shares in Millions, $ in Millions
12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Information Related to Stock Options [Abstract]      
Pretax expense for stock options $ 12 $ 12 $ 11
After-tax expense for stock options 8 8 7
Proceeds from stock options exercised 52 54 121
Income tax benefit related to stock options exercised      
Tax benefit classified in operating activities in the Consolidated Statements of Cash Flows 4 4 3
Excess tax benefit classified in financing activities in the Consolidated Statements of Cash Flows 1 15 22
Intrinsic value of stock options exercised 44 55 102
Total fair value of stock options vesting $ 12 $ 12 $ 11
Stock options exercised, shares 1.4 1.5 3.6
Non-vested stock option compensation expense not yet recognized $ 11    
Non-vested stock options weighted-average period for total compensation expense to be recognized 1 year 8 months