v2.4.0.8
Amortized Cost and Fair Value of Held to Maturity Investments (Detail) (USD $)
In Thousands, unless otherwise specified
Jun. 30, 2013
Sep. 30, 2012
Schedule of Held-to-maturity Securities [Line Items]    
Amortized Cost $ 63,529 $ 55,988
HeldToMaturitySecuritiesGrossUnrecognizedHoldingGains 18 13
HeldToMaturitySecuritiesGrossUnrecognizedHoldingLosses (28) (11)
Estimated Fair Market Value 63,519 55,990
Municipal bonds, due in less than 1 year
   
Schedule of Held-to-maturity Securities [Line Items]    
Amortized Cost 27,085 23,402
HeldToMaturitySecuritiesGrossUnrecognizedHoldingGains 11 2
HeldToMaturitySecuritiesGrossUnrecognizedHoldingLosses 0 (8)
Estimated Fair Market Value 27,096 23,396
Corporate bonds, due in less than 1 year
   
Schedule of Held-to-maturity Securities [Line Items]    
Amortized Cost 16,239 18,210
HeldToMaturitySecuritiesGrossUnrecognizedHoldingGains 1 8
HeldToMaturitySecuritiesGrossUnrecognizedHoldingLosses (23) (3)
Estimated Fair Market Value 16,217 18,215
Certificates of deposit, due in less than 1 year
   
Schedule of Held-to-maturity Securities [Line Items]    
Amortized Cost 6,093 9,843
HeldToMaturitySecuritiesGrossUnrecognizedHoldingGains 0 3
HeldToMaturitySecuritiesGrossUnrecognizedHoldingLosses 0 0
Estimated Fair Market Value 6,093 9,846
Municipal bonds, due in 1 - 2 years
   
Schedule of Held-to-maturity Securities [Line Items]    
Amortized Cost 12,008 170
HeldToMaturitySecuritiesGrossUnrecognizedHoldingGains 6 0
HeldToMaturitySecuritiesGrossUnrecognizedHoldingLosses (4) 0
Estimated Fair Market Value 12,010 170
Corporate bonds, due in 1-2 years
   
Schedule of Held-to-maturity Securities [Line Items]    
Amortized Cost 628 0
HeldToMaturitySecuritiesGrossUnrecognizedHoldingGains 0 0
HeldToMaturitySecuritiesGrossUnrecognizedHoldingLosses (1) 0
Estimated Fair Market Value 627 0
Certificates of deposit, due in 1- 2 years
   
Schedule of Held-to-maturity Securities [Line Items]    
Amortized Cost 1,476 4,363
HeldToMaturitySecuritiesGrossUnrecognizedHoldingGains 0 0
HeldToMaturitySecuritiesGrossUnrecognizedHoldingLosses 0 0
Estimated Fair Market Value $ 1,476 $ 4,363