Stock-based Compensation - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	9 Months Ended		3 Months Ended	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014 Severance and Related Restructuring Costs [Member]	Sep. 30, 2014 Severance and Related Restructuring Costs [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Fair value assumptions method used	We use a Black-Scholes model to determine the fair value of certain share-based awards, such as stock options. Additionally, we use a Monte Carlo model to determine the fair value of certain share-based awards that contain market and performance-based conditions.
Stock-based compensation charges	$ 14,387	$ 15,492	$ 1,300	$ 2,000