Annual report pursuant to Section 13 and 15(d)

Share Based Compensation - Summary of Activity Under all Share-Based Compensation Plans (Detail)

v2.4.0.6
Share Based Compensation - Summary of Activity Under all Share-Based Compensation Plans (Detail) (USD $)
In Millions, except Share data, unless otherwise specified
 12 Months Ended
Dec. 31, 2012
Y
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Awards Outstanding, Beginning Balance 11,169,000
Granted, Awards 2,109,000
Exercised, Awards (1,862,000)
Forfeited, Awards (83,000)
Awards Outstanding, Ending Balance 11,333,000
Awards Exercisable, Ending Balance 5,751,000
Weighted Average Exercise Price Outstanding, Beginning Balance $ 22.54
Granted, Weighted Average Exercise Price $ 45.10
Exercised, Weighted Average Exercise Price $ 10.23
Forfeited, Weighted Average Exercise Price $ 41.54
Weighted Average Exercise Price Outstanding, Ending Balance $ 28.62
Exercisable, Weighted Average Exercise Price, Ending Balance $ 18.29
Weighted Average Remaining Contractual Term Outstanding, Beginning Balance 5.5
Weighted Average Remaining Contractual Term Outstanding, Ending Balance 5.9
Exercisable, Weighted Average Remaining Contractual Term, Ending Balance 3.9
Aggregate Intrinsic Value Outstanding, Beginning balance $ 332.8
Aggregate Intrinsic Value Outstanding, Ending balance 119.1
Exercisable, Aggregate Intrinsic Value, Ending Balance $ 89.8
Outstanding and nonvested at December 31, 2011, Weighted Average Grant Date Fair Value $ 12.25
Granted, Weighted Average Grant Date Fair Value   
Vested, Weighted Average Grant Date Fair Value $ 12.71
Forfeited, Weighted Average Grant Date Fair Value $ 6.82
Outstanding and nonvested at Dec 31, 2012, Weighted Average Grant Date Fair Value $ 11.70
Independent Director's SARs [Member]
  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Outstanding and nonvested at December 31, 2011, Shares 717,600
Granted, shares   
Vested, Shares (395,700)
Forfeited, Shares (300)
Outstanding and nonvested at December 31, 2012, Shares 321,600