Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
OPERATING ACTIVITIES
Net income	$ 886.3	$ 750.7	$ 533.5
Adjustments to reconcile net income to net cash (used in) provided by operating activities:
Depreciation and amortization	61.0	54.1	38.4
Amortization of discounts and fees	5.4	5.6	27.4
Stock based compensation expense	49.0	42.2	26.2
Excess income tax benefit from employee stock awards	(10.0)	(12.3)	(0.6)
Deferred income taxes	75.3	3.1	17.4
Inventory and land option charges	31.4	60.3	85.2
Gain on sale of debt securities collateralized by residential real estate	(4.5)	0.0	0.0
Goodwill impairment	7.2	9.8	0.0
Changes in operating assets and liabilities:
(Increase) decrease in construction in progress and finished homes	(496.2)	63.1	(918.2)
Increase in residential land and lots — developed, under development, held for development and held for sale	(10.3)	(152.6)	(513.6)
(Increase) decrease in other assets	(16.3)	(29.8)	8.8
Increase in mortgage loans held for sale	(12.4)	(154.1)	(81.8)
Increase in accounts payable, accrued expenses and other liabilities	52.1	60.3	115.9
Net cash (used in) provided by operating activities	618.0	700.4	(661.4)
INVESTING ACTIVITIES
Purchases of property and equipment	(86.1)	(56.1)	(100.2)
Proceeds from the sale of property and equipment to a related party	0.0	56.0	0.0
Decrease (increase) in restricted cash	0.2	(0.7)	67.8
Net principal decrease (increase) of other mortgage loans and real estate owned	19.7	(8.9)	(5.6)
Proceeds from sale (purchases) of debt securities collateralized by residential real estate	35.8	(14.8)	0.0
Payments related to acquisition of a business	(82.2)	(70.9)	(244.1)
Net cash used in investing activities	(112.6)	(95.4)	(282.1)
FINANCING ACTIVITIES
Proceeds from notes payable	0.0	1,590.7	1,427.6
Repayment of notes payable	(549.7)	(1,456.2)	(796.9)
Proceeds from stock associated with certain employee benefit plans	72.4	61.8	45.2
Income tax benefit from stock option exercises	10.0	12.3	0.6
Cash dividends paid	(118.7)	(91.6)	(48.6)
Net cash provided by (used in) financing activities	(586.0)	117.0	627.9
Increase (decrease) in cash and cash equivalents	(80.6)	722.0	(315.6)
Cash and cash equivalents at beginning of year	1,383.8	661.8	977.4
Cash and cash equivalents at end of year	1,303.2	1,383.8	661.8
Supplemental cash flow information:
Income taxes paid (refunded), net	389.9	334.0	279.8
Supplemental disclosures of non-cash activities:
Notes payable issued for inventory	4.2	9.7	0.0
Stock issued under employee incentive plans	20.1	8.3	5.5
Accrual for holdback payment related to acquisition	9.7	0.0	0.0
Conversion of 2% convertible senior notes into equity	0.0	0.0	498.6
Notes payable assumed to purchase land investment	0.0	0.0	18.6
Note receivable related to sale of land	$ 0.0	$ 0.0	$ 5.0