Share-Based Compensation to Employees (Restricted Stock Units) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Share-based compensation to employees
Allocated share-based compensation expense	$ 12,628	$ 2,676	$ 1,468
RSU [Member]
Units
Outstanding, beginning of period (in shares)	630	348	232
Granted (in shares)	92	286	116
Vested (in shares)	0	0	0
Forfeited (in shares)	(13)	(4)	0
Outstanding, end of period (in shares)	709	630	348
Weighted Average Grant Date Fair Value
Outstanding, beginning of period (in dollars per share)	$ 13.74	$ 14.20	$ 16.26
Granted (in dollars per share)	$ 18.85	$ 13.03	$ 10.47
Vested (in dollars per share)	$ 0.00	$ 0.00	$ 0.00
Forfeited (in dollars per share)	$ 13.03	$ 13.03	$ 0.00
Outstanding, end of period (in dollars per share)	$ 15.50	$ 13.74	$ 14.20