Property and Equipment - Other Items Related to Property and Equipment (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Property Plant And Equipment [Abstract]
Unamortized computer software costs	$ 43,317	$ 48,873
Amortization of capitalized software	8,688	7,912	6,180
Total depreciation expense charged to income	$ 24,727	$ 21,504	$ 20,680