v3.21.2
Stockholders' Equity - SAR and Option Activity (Details)
$ / shares in Units, shares in Thousands, $ in Millions
 6 Months Ended 12 Months Ended
Jun. 30, 2021
USD ($)
$ / shares
shares
Dec. 31, 2020
USD ($)
$ / shares
shares
Share-Based Compensation Arrangement By Share-Based Payment Award, Options And Equity Instruments Other Than Options, Nonvested, Number Of Shares [Abstract]    
Weighted-Average Exercise Price Per Share, Outstanding (in dollars per share) | $ / shares $ 12.87  
Weighted-Average Exercise Price Per Share, Awards granted (in dollars per share) | $ / shares 14.68  
Weighted-Average Exercise Price Per Share, Awards exercised (in dollars per share) | $ / shares 12.30  
Weighted-Average Exercise Price Per Share, Awards canceled and forfeited (in dollars per share) | $ / shares 18.24  
Weighted-Average Exercise Price Per Share, Outstanding (in dollars per share) | $ / shares 13.03 $ 12.87
Weighted-Average Exercise Price Per Share, Vested and expected to vest (in dollars per share) | $ / shares 8.39  
Weighted-Average Exercise Price Per Share, Exercisable (in dollars per share) | $ / shares $ 8.39  
Share-Based Compensation Arrangement By Share-based Payment Award, Options And Equity Instruments Other Than Options, Nonvested, Additional Disclosures [Abstract]    
Weighted-Average Contractual Life, Outstanding 4 years 7 days 4 years 11 months 19 days
Weighted-Average Contractual Life, Vested and expected to vest 3 years 5 months 12 days  
Weighted-Average Contractual Life, Exercisable 3 years 5 months 12 days  
Aggregate Intrinsic Value, Outstanding | $ $ 867 $ 1,104
Aggregate Intrinsic Value, Vested and expected to vest | $ 752  
Aggregate Intrinsic Value, Exercisable | $ $ 752  
SARs Outstanding Number of SARs    
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]    
Shares outstanding 229  
Awards granted 0  
Awards exercised (48)  
Awards Canceled and Forfeited (in shares) (2)  
Shares outstanding 179 229
Vested and expected to vest 138  
Exercisable 138  
Stock options    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]    
Options outstanding 28,734  
Awards granted 945  
Awards exercised (6,177)  
Awards canceled and forfeited (300)  
Options outstanding 23,202 28,734
Vested and expected to vest 17,773  
Exercisable 17,773