STOCKHOLDERS EQUITY (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		12 Months Ended
	Sep. 30, 2012	Dec. 31, 2011	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010
Capital Stock Activity [Rollforward]
Beginning Balance (in shares)		27,652,336	27,652,336	26,384,715	26,143,116
Exercise of stock options (in shares)			976,645	1,085,965	74,019
Restricted stock under EIP, net of forfeitures (in shares)			159,879	115,069	127,390
Restricted stock under Deposit Share Plan, net of forfeitures (in shares)			5,022	5,223	2,140
Common stock under ESPP (in shares)			70,645	61,364	38,050
Ending Balance (in shares)	28,864,527		28,864,527	27,652,336	26,384,715
Treasury Stock [Abstract]
Beginning Balance (in shares)		4,715,577	4,715,577	3,446,069	2,698,234
Repurchases of common stock under share repurchase plans (in shares)			929,407	1,235,668	723,184
Repurchases of common stock - other (in shares)			37,304	33,840	24,651
Ending Balance (in shares)	5,682,288		5,682,288	4,715,577	3,446,069
Number of votes each common stockholder is entitled to on matter submitted to a vote of stockholders	1		1
Number of authorized shares of common stock (in shares)	200,000,000		200,000,000	200,000,000
Share repurchase program, value of shares authorized to be repurchased	$ 130,000	$ 150,000
Cost of shares repurchased			$ 33,026	$ 54,106	$ 24,998