Consolidated Balance Sheets (Parenthetical) (Unaudited) - USD ($) $ in Millions	Mar. 31, 2018	Sep. 30, 2017
ASSETS
Valuation allowance for deferred income taxes	$ 25.9	$ 11.2
EQUITY
Preferred stock, par value (in dollars per share)	$ 0.1	$ 0.1
Preferred stock, shares authorized	30,000,000	30,000,000
Preferred stock, shares issued	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	1,000,000,000	1,000,000,000
Common stock, shares issued	387,459,588	384,036,150
Common stock, shares outstanding	377,409,517	374,986,079
Treasury stock, shares	10,050,071	9,050,071