Summary of Stock Option Activity (Parenthetical) (Detail)	12 Months Ended
	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares, Granted	825,750	[1]
Outstanding amount of stock appreciation right units	2,816,691
Exercisable amount of stock appreciation right units	1,549,633
Stock Appreciation Rights (SARs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares, Granted	693,750
Maximum | Stock Appreciation Rights (SARs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum percentage of stock appreciation right units	75.00%

[1] Includes 693,750 SAR units which are convertible for a maximum number of shares of the Company's common stock equal to 75% of the SAR units subject to the grant.