Income Taxes - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended			9 Months Ended
	Sep. 30, 2013	Jun. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Income Tax Disclosure [Abstract]
Income before taxes	$ 7,553		$ 10,035	$ 12,689	$ 20,017
Provision for income taxes	$ 3,429		$ 5,924	$ 7,844	$ 13,375
Effective income tax rate	45.40%		59.00%	61.80%	66.80%
Adjusted full-year expected annualized tax rate	68.00%	64.00%