Income Taxes - Additional Information (Detail) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Income tax provision	$ 1,435,000	$ 2,196,000	$ 3,904,000	$ 1,904,000
Liability for income taxes associated with uncertain tax positions	7,994,000		7,994,000
Tax benefits associated with potential transfer pricing adjustments			2,833,000
Tax benefits associated with state income taxes	2,588,000		2,588,000
Net amount of unrecognized tax benefit related to uncertain tax positions that would impact, if recognized, effective income tax rate	2,573,000		2,573,000
Interest and penalties related to income tax matters	443,000	28,000	180,000	90,000
Income tax accrued for payment of interest and penalties	$ 1,065,000		$ 1,065,000		$ 1,245,000