Equities Changes in Equity (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Nov. 30, 2012	Nov. 30, 2011
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' Equity Attributable to Parent	$ 4,455,341	$ 3,915,592
Net Income (Loss) Attributable to Parent	343,707	416,208
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	245	(4,773)
Retirements Of Equities	(2,378)	(2,447)
Payments of Ordinary Dividends, Preferred Stock and Preference Stock	(6,136)	(6,136)
Change in Accrued Dividends and Equities Payable	147,091	(168,291)
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests		(96,720)
Stockholders' Equity, Other	(660)	(335)
Stockholders' Equity Attributable to Parent	4,663,737	4,071,145
Stockholders' Equity Attributable to Noncontrolling Interest	17,982
Net income attributable to noncontrolling interests	2,174	72,674
Stockholders' Equity Attributable to Noncontrolling Interest	21,302	13,103
Capital equity certificates [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends and equity retirement determination	2,378	2,447
Equity Certificates Issued During Period, Value, New Issues	14,240	11,509
Capital Reserves [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends and equity retirement determination	4,091	4,091
Noncontrolling Interest [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Changes in dividends and equities payable for noncontrolling interests		71,740
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests		(337,145)
Stockholders' Equity, Other	1,146	(179)
Stockholders' Equity Attributable to Noncontrolling Interest		349,728
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders		(5,779)
Distributions accrued for noncontrolling interests		$ (5,544)