Capitalized Interest (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Rollforward of capitalized interest
Capitalized interest, beginning of period		$ 214.5	$ 212.2	$ 208.0	$ 198.5
Interest incurred	[1]	35.4	43.2	118.0	126.2
Interest charged to cost of sales		(43.3)	(42.8)	(119.4)	(112.1)
Capitalized interest, end of period		206.6	212.6	206.6	212.6
Financial Services [Member]
Rollforward of capitalized interest
Interest incurred		$ 2.4	$ 2.1	$ 5.9	$ 5.2

[1] Interest incurred includes interest incurred on the Company's financial services mortgage repurchase facility of $2.4 million and $5.9 million in the three and nine months ended June 30, 2016, respectively, and $2.1 million and $5.2 million in the same periods of 2015.