Earnings Per Share (Details) (USD $)	3 Months Ended								12 Months Ended
	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2010
Basic EPS
Net income allocated to controlling interests	$ 65,336,000	$ 68,234,000	$ 66,939,000	$ 59,704,000	$ 43,856,000	$ 69,236,000	$ 48,103,000	$ 33,242,000	$ 260,213,000	$ 194,437,000	$ 120,597,000
Less: Income allocated to participating securities									(8,206,000)	(9,324,000)	(4,323,000)
Income available to common shareholders									$ 252,007,000	$ 185,113,000	$ 116,274,000
Shares									69,944,000.00	70,523,000	57,135,000
Per share amount	$ 0.91	$ 0.95	$ 0.92	$ 0.82	$ 0.59	$ 0.94	$ 0.65	$ 0.45	$ 3.60	$ 2.62	$ 2.04
Diluted EPS
Share-based compensation awards, shares									320,000	64,000	115,000
Shares									70,264,000	70,587,000	57,250,000
Per share amount	$ 0.91	$ 0.95	$ 0.92	$ 0.82	$ 0.59	$ 0.94	$ 0.65	$ 0.45	$ 3.59	$ 2.62	$ 2.03
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount											108,900