XML 64 R36.htm IDEA: XBRL DOCUMENT v2.4.0.6
Changes in Allowance for Doubtful Accounts (Detail) (USD $)
In Thousands, unless otherwise specified
 12 Months Ended
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Dec. 31, 2008
Balance at beginning of year $ 1,233 $ 2,241 $ 2,790 $ 2,183
(Income) expense (153) (981) 60  
Write-offs, net (222) (27) (609)  
Balance at end of year $ 858 $ 1,233 $ 2,241 $ 2,183