Stock-Based Compensation - Performance-based Equity Awards - Additional Information (Detail) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014 Minimum [Member]	Sep. 30, 2014 Minimum [Member] 2014 LTIP - One-year Revenue Goals [Member]	Sep. 30, 2014 Maximum [Member]	Sep. 30, 2014 Maximum [Member] 2014 LTIP - One-year Revenue Goals [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares earned		190,000		380,000
Amortized cost	$ 0.2		$ 0.5