Stock and Incentive Programs for Employees - Additional Information (Detail) (USD $)	12 Months Ended			20 Months Ended		0 Months Ended	1 Months Ended	12 Months Ended																		12 Months Ended
	Dec. 31, 2012 CompensationPlan	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Share Repurchase Program	May 02, 2011 Two Thousand And Eight Share Repurchase Program	May 10, 2011 Accelerated Share Repurchase Program	Nov. 17, 2011 Accelerated Share Repurchase Program	Dec. 31, 2011 Accelerated Share Repurchase Program	Dec. 31, 2012 Restricted Stock	Dec. 31, 2011 Restricted Stock	Dec. 31, 2010 Restricted Stock	Dec. 31, 2012 Restricted Stock Director	Dec. 31, 2011 Restricted Stock Director	Dec. 31, 2010 Restricted Stock Director	Dec. 31, 2012 Restricted Stock Between January 2008 And January 2009 Director	Dec. 31, 2012 Restricted Stock Minimum	Dec. 31, 2012 Restricted Stock Maximum Y	Dec. 31, 2012 Stock Options	Dec. 31, 2011 Stock Options	Dec. 31, 2010 Stock Options	Dec. 31, 2012 Stock Options Minimum	Dec. 31, 2012 Stock Options Maximum	Dec. 31, 2012 Stock Options Maximum Prior To November Twenty Zero Four And After December Twenty Zero SIx Y	Dec. 31, 2012 Stock Options Maximum After Retirement Date Y	Dec. 31, 2012 Stock Compensation Plan	Dec. 31, 2012 Stock Compensation Plan Maximum Y	Dec. 31, 2012 Performance Share Unit Awards	Dec. 31, 2011 Performance Share Unit Awards	Dec. 31, 2010 Performance Share Unit Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting term															3 years	3 years	4 years				3 years	4 years	4 years				3 years
Share-based compensation expense	$ 25,400,000	$ 28,300,000	$ 28,600,000
Share-based compensation expense, income tax benefit	9,900,000	11,000,000	11,200,000
Unrecognized share-based compensation cost	20,900,000								16,000,000									3,200,000									1,700,000
Unrecognized compensation expense, weighted-average period of recognition	2 years 1 month 6 days								2 years									2 years 6 months									1 year 9 months 18 days
Number of active Share-based compensation plan	1
Number of terminated or expired share-based compensation plans	4
Common stock reserved and authorized (in shares)																									10,000,000
Shares authorized and available for grant under the 2004 PIP																									9,800,000
Award term (in years)																	10						10	5		10
Amount payable as a percentage of initial award, contingent upon maximum performance																											100.00%
Stock options granted	1,221,000	200,000	540,000
Weighted average fair market value of options granted	$ 2.96	$ 4.39	$ 4.81
Intrinsic value of options exercised	1,200,000	1,000,000	3,000,000
Share-based compensation (income) expense									21,000,000	24,400,000	25,500,000	(200,000)	100,000	400,000				3,200,000	2,700,000	3,100,000							1,200,000	1,200,000	0
Cash received from option exercises	1,400,000	1,000,000	2,400,000
Tax benefit realized for tax deduction from option exercises	500,000	400,000	1,100,000
Excess tax benefits shown as financing cash inflows									3,200,000	5,700,000	6,000,000							400,000	300,000	800,000
Equity instruments other than options expected to vest, shares									3,100,000
Equity instruments other than options expected to vest, weighted-average grant date fair value									$ 11.72
Granted, Shares									1,048,000																		233,000	235,000	0
Equity instruments other than options, payout range , minimum																											116,500	117,500
Equity instruments other than options, payout range, maximum																											233,000	235,000
Equity instruments other than options, percentage of expected payout																												50.00%
Equity instruments other than options, outstanding shares									3,246,000	4,989,000		147,263	147,263	145,459
Stock repurchase program, authorized amount				1,000,000,000
Stock repurchase program, shares authorized					10,000,000
Treasury stock, shares acquired	0		0			19,900,000	9,300,000	29,200,000
Cash payment for share repurchase under ASR program								$ 500,000,000