Reconciliation of Valuation Allowance (Detail) (USD $)
In Thousands, unless otherwise specified
3 Months Ended 12 Months Ended
Dec. 31, 2012
Jun. 30, 2012
Dec. 31, 2013
Dec. 31, 2011
Dec. 31, 2013
Addition to Valuation Allowance
Dec. 31, 2012
Valuation Allowance Release
Valuation Allowance [Line Items]            
Balance at beginning of the year     $ 6,076 $ 40,188    
Valuation allowance additions (release) (17,800) (20,700)     4,419 (38,531)
Balance at end of the year $ 1,657   $ 6,076 $ 40,188