Share-Based Compensation Expenses (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option plan	$ 4,286	$ 2,326	$ 12,643	$ 7,047
Other share-based awards	17,053	3,572	44,349	43,899
Total share-based compensation before tax	21,339	5,898	56,992	50,946
Tax benefit	7,965	2,243	21,318	19,338
Total share-based compensation expense included in net income	$ 13,374	$ 3,655	$ 35,674	$ 31,608