Segment Revenues and Segment Income (Parenthetical) (Detail) (USD $)	3 Months Ended	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Segment Reporting Information [Line Items]
Expense for incentive compensation plans		$ 65,000,000	$ 108,100,000	$ 75,300,000
Share-based compensation expense		61,651,000	63,277,000	53,476,000
Litigation charge	137,800,000
Corporate and Other
Segment Reporting Information [Line Items]
Expense for incentive compensation plans		65,000,000	108,100,000	75,300,000
Severance and other termination-related costs		17,600,000	13,400,000	14,900,000
Share-based compensation expense		61,700,000	63,300,000	53,500,000
Litigation charge			137,800,000
Legal settlement				$ 7,500,000