Quarterly report pursuant to Section 13 or 15(d)

Restricted Common Stock and Stock Appreciation Rights ("SARs") - Formula Settlement Value and Compensation Cost Related to Non Vested Stock and SARs (Detail)

v2.4.0.8
Restricted Common Stock and Stock Appreciation Rights ("SARs") - Formula Settlement Value and Compensation Cost Related to Non Vested Stock and SARs (Detail) (USD $)
In Thousands, unless otherwise specified
9 Months Ended
Sep. 30, 2013
Sep. 30, 2012
Restricted common stock [Member]
   
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Formula settlement vale and compensation cost $ 271 $ 421
SARs [Member]
   
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Formula settlement vale and compensation cost $ 225 $ 313