Summary of Activity Related to Target Number of Shares Awarded and Actual Number of Shares Earned Under 2007 Plan (Detail) (2007 Plan, USD $) In Thousands, except Per Share data, unless otherwise specified	9 Months Ended
	Jun. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Beginning Balance, Outstanding number of shares	158
Shares awarded, Number of shares award forfeited (various awards)	(38)
Ending Balance, Outstanding number of shares	154
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Beginning Balance, Outstanding weighted average fair value at date of grant	$ 18.30
Shares not earned, Weighted average fair value at date of grant awards forfeited (various awards)	$ 17.00
Ending Balance, Outstanding weighted average fair value at date of grant	$ 17.85
Restricted shares
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Shares awarded, Number of shares	12
Shares earned, Number of shares	5
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Shares earned, Weighted average fair value at date of grant	$ 15.50
Shares not earned, Weighted average fair value at date of grant	$ 22.00
Performance shares
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Shares awarded, Number of shares	60
Shares earned, Number of shares	33
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Shares earned, Weighted average fair value at date of grant	$ 15.98
Shares not earned, Weighted average fair value at date of grant	$ 16.05