EARNINGS PER SHARE (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Numerator:
Earnings available to common shares	$ 13,242	$ 12,789	$ 29,187	$ 42,373
Denominator:
Weighted average common shares (Denominator for basic calculation)	23,120,000	23,119,000	22,778,000	22,931,000
Weighted average effect of dilutive securities:
Share-based compensation	819,000	678,000	769,000	594,000
Diluted weighted average common shares (Denominator for diluted calculation)	23,939,000	23,797,000	23,547,000	23,525,000
Earnings per share:
Basic	$ 0.57	$ 0.55	$ 1.28	$ 1.85
Diluted	$ 0.55	$ 0.54	$ 1.24	$ 1.80
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Outstanding stock options excluded from diluted earnings	1,300,000	1,300,000	1,300,000	1,300,000