Stock-Based Compensation (Stock-Based Compensation Expense) (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
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total			$ 7,942	$ 10,016
Stock-Based Compensation Expense [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock options	2,190	2,073	6,549	6,686
Non-vested stock awards/stock units	354	360	1,063	3,000
Deferred stock units			330	330
Total	$ 2,544	$ 2,433	$ 7,942	$ 10,016