Stockholders' Equity - Additional Information (Detail) (USD $)	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2014	Dec. 31, 2013	Oct. 23, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Total amount authorized under repurchase program				$ 50,000,000
Stock repurchase program, period in force		2 years
Number of shares repurchased under stock repurchase program		1,016,169	75,000
Total common stock aggregate purchase price		28,300,000	2,200,000
Share based compensation, capitalized	39,000	102,000
Unrecognized compensation expense	$ 21,800,000	$ 21,800,000
Weighted average period, years		1 year 9 months 18 days