Quarterly report pursuant to Section 13 or 15(d)

Commitments and Contingencies Additional Information (Detail)

v2.4.0.6
Commitments and Contingencies Additional Information (Detail) (USD $)
Dec. 31, 2012
Sep. 30, 2012
Loss Contingencies [Line Items]    
Amount of settlement payment $ 7,800,000 $ (7,750,000)
Sales Tax Audit [Member]
   
Loss Contingencies [Line Items]    
Contingent liability/reserve   0
Other Legal Matters [Member]
   
Loss Contingencies [Line Items]    
Contingent liability/reserve   $ 0