Schedule of Stock Compensation Expense (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Restricted stock	$ 4,129	$ 4,744	$ 4,370
Stock options	2,825	2,435	2,343
Performance stock	3,383	2,831	1,019
Total compensation expense before income taxes	10,337	10,010	7,732
Income tax benefit	3,810	3,700	2,825
Total compensation expense, net of income tax benefit	$ 6,527	$ 6,310	$ 4,907