Condensed Consolidated Statements of Operations - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017
Income Statement [Abstract]
Sales and operating revenues	$ 1,041.0	$ 917.7	$ 1,970.6	$ 1,712.5
Cost of sales and operating expenses	925.3	815.5	1,748.0	1,525.9
Gross profit	115.7	102.2	222.6	186.6
Selling, general and administrative expenses	85.9	80.0	170.7	154.5
Transaction related costs	0.0	0.3	0.1	1.1
Change in fair value of contingent consideration obligations	12.6	10.0	(6.0)	20.6
Operating income	17.2	11.9	57.8	10.4
Other income, net	0.4	0.2	0.5	2.6
Interest income (expense)
Interest income	0.1	0.1	0.2	0.2
Interest expense	(12.7)	(12.5)	(25.7)	(24.5)
Net income (loss) before income taxes	5.0	(0.3)	32.8	(11.3)
Income tax expense (benefit)	4.6	0.8	5.9	(1.9)
Net income (loss) attributable to Nexeo Solutions, Inc.	$ 0.4	$ (1.1)	$ 26.9	$ (9.4)
Net income (loss) per share available to common stockholders
Basic (USD per share)	$ 0.01	$ (0.01)	$ 0.35	$ (0.12)
Diluted (USD per share)	$ 0.01	$ (0.01)	$ 0.35	$ (0.12)
Weighted average number of common shares outstanding
Basic (in shares)	76,795,742	76,746,168	76,794,618	76,746,168
Diluted (in shares)	77,281,397	76,746,168	77,209,536	76,746,168