v2.4.0.8
Summary of Fair Value Transfers Between Level I and Level II (Detail) (USD $)
In Thousands, unless otherwise specified
 3 Months Ended 9 Months Ended
Sep. 30, 2013
Sep. 30, 2014
Sep. 30, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Transfers from Level I into Level II     $ 31 [1]
Transfers from Level II into Level I $ 41,155 [2] $ 67,327 [2] $ 1,308 [2]
[1] Transfers out of Level I represent those financial instruments for which restrictions exist and adjustments were made to an otherwise observable price to reflect fair value at the reporting date.
[2] Transfers into Level I represent those financial instruments for which an unadjusted quoted price in an active market became available for the identical asset.