Income Taxes - Schedule of Effective Income Tax Rate (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Computed “expected” tax provision (benefit)	$ 15,500,000	$ (100,000)	$ 6,700,000
Change in income tax resulting from:
State taxes, net of federal benefit	2,100,000	(8,400,000)	1,200,000
Foreign taxes	100,000	200,000	300,000
Change in valuation allowance		(126,000,000)	(2,200,000)
Other	700,000	200,000	100,000
Total provision (benefit) for taxes	$ 18,444,000	$ (134,137,000)	$ 6,112,000