Notes Payable (Details) (USD $)	Sep. 30, 2013		Sep. 30, 2012
Unsecured:
Notes payable	$ 3,509,000,000		$ 2,493,100,000
Homebuilding [Member]
Unsecured:
Notes payable	3,270,400,000		2,305,300,000
Homebuilding [Member] | Revolving credit facility, maturing 2018 [Member]
Summary of notes payable at principal amounts, net of unamortized discounts
Line of credit, amount outstanding	0		0
Homebuilding [Member] | 6.875% senior notes due 2013 [Member]
Unsecured:
Senior notes, stated interest rate			6.875%
Notes payable	0		171,700,000
Homebuilding [Member] | 6.125% senior notes due 2014, net [Member]
Unsecured:
Senior notes, stated interest rate	6.125%
Notes payable	145,800,000		145,500,000
Homebuilding [Member] | 2% convertible senior notes due 2014, net [Member]
Unsecured:
Senior notes, stated interest rate	2.00%
Notes payable	478,700,000	[1]	447,000,000	[1]
Homebuilding [Member] | 5.625% senior notes due 2014, net [Member]
Unsecured:
Senior notes, stated interest rate	5.625%
Notes payable	137,800,000		137,600,000
Homebuilding [Member] | 5.25% senior notes due 2015, net [Member]
Unsecured:
Senior notes, stated interest rate	5.25%
Notes payable	157,500,000		157,400,000
Homebuilding [Member] | 5.625% senior notes due 2016, net [Member]
Unsecured:
Senior notes, stated interest rate	5.625%
Notes payable	169,700,000		169,600,000
Homebuilding [Member] | 6.5% senior notes due 2016, net [Member]
Unsecured:
Senior notes, stated interest rate	6.50%
Notes payable	372,500,000		372,400,000
Homebuilding [Member] | 4.75% senior notes due 2017 [Member]
Unsecured:
Senior notes, stated interest rate	4.75%
Notes payable	350,000,000		350,000,000
Homebuilding [Member] | 3.625% senior notes due 2018 [Member]
Unsecured:
Senior notes, stated interest rate	3.625%
Notes payable	400,000,000		0
Homebuilding [Member] | 4.375% senior notes due 2022 [Member]
Unsecured:
Senior notes, stated interest rate	4.375%
Notes payable	350,000,000		350,000,000
Homebuilding [Member] | 4.75 senior notes due 2023 [Member]
Unsecured:
Senior notes, stated interest rate	4.75%
Notes payable	300,000,000		0
Homebuilding [Member] | 5.75% senior notes due 2023 [Member]
Unsecured:
Senior notes, stated interest rate	5.75%
Notes payable	400,000,000		0
Homebuilding [Member] | Other secured [Member]
Unsecured:
Notes payable	8,400,000		4,100,000
Financial Services [Member]
Unsecured:
Assets Sold under Agreements to Repurchase, Repurchase Liability	$ 238,600,000	[2]	$ 187,800,000	[2]

[1] The fair value is determined based on quoted market prices of recent transactions of the notes, which is classified as Level 2 within the fair value hierarchy.

[2] The fair value approximates carrying value due to its short-term nature, short maturity or floating interest rate terms, as applicable.