Earnings Per Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010
Basic Earnings per Share from Continuing Operations
Income (loss) from continuing operations	$ (286)	$ 28,014	$ 102,084	$ 62,384	$ 237	$ (3,150)	$ 124,293	$ 68,208	$ 192,196	$ 189,588	$ 189,851
Less: Income (loss) from continuing operations allocated to participating securities									793	1,980	1,943
Income (loss) from continuing operations available to common shareholders									191,403	187,608	187,908
Income Loss From Continuing Operations Per Basic Share	$ 0.00	$ 0.31	$ 1.12	$ 0.68	$ 0.00	$ (0.04)	$ 1.36	$ 0.75	$ 2.12	$ 2.08	$ 2.05
Basic Earnings per Share from Discontinued Operations
Net income (loss) from discontinued operations									24,521	18,013	15,988
Less: Income (loss) from discontinued operations allocated to participating securities									101	188	164
Income (loss) from discontinued operations available to common shareholders									24,420	17,825	15,824
Income (loss) from discontinued operations per share - Basic	$ 0.09	$ 0.03	$ 0.08	$ 0.07	$ 0.02	$ 0.03	$ 0.09	$ 0.06	$ 0.27	$ 0.20	$ 0.17
Basic net income (loss) per share	$ 0.09	$ 0.34	$ 1.20	$ 0.75	$ 0.02	$ (0.01)	$ 1.45	$ 0.81	$ 2.39	$ 2.28	$ 2.22
Basic									90,150	90,201	91,852
Diluted Earnings per Share from Continuing Operations
Effect of dilutive stock options and other shares									4	4	5
Income (loss) from continuing operations available to common shareholders									191,407	187,612	187,913
Additional dilutive stock options and other shares									1,022	451	570
Diluted									91,172	90,652	92,422
Income Loss From Continuing Operations Per Diluted Share	$ 0.00	$ 0.31	$ 1.12	$ 0.68	$ 0.00	$ (0.04)	$ 1.36	$ 0.75	$ 2.10	$ 2.07	$ 2.03
Diluted Earnings per Share from Discontinued Operations
Effect of dilutive stock options and other shares									0	0	0
Income (loss) from discontinued operations available to common shareholders									$ 24,420	$ 17,825	$ 15,824
Additional dilutive stock options and other shares									1,022	451	570
Diluted weighted average shares outstanding									91,172	90,652	92,422
Income (loss) from discontinued operations per share - Diluted	$ 0.09	$ 0.03	$ 0.08	$ 0.07	$ 0.02	$ 0.03	$ 0.09	$ 0.06	$ 0.27	$ 0.20	$ 0.17
Diluted net income (loss) per share	$ 0.09	$ 0.34	$ 1.20	$ 0.75	$ 0.02	$ (0.01)	$ 1.45	$ 0.81	$ 2.37	$ 2.27	$ 2.20