Acquisitions - Narrative (Details)			1 Months Ended		2 Months Ended	3 Months Ended				8 Months Ended	9 Months Ended			12 Months Ended
	Apr. 03, 2017 USD ($)	Jun. 09, 2016 USD ($) location merger	Apr. 30, 2017 USD ($)	Dec. 31, 2016 USD ($)	Jun. 08, 2016 USD ($)	Jun. 30, 2017 USD ($) $ / shares shares	Mar. 31, 2017 USD ($)	Jun. 30, 2016 USD ($) shares		Jun. 08, 2016 USD ($)	Jun. 30, 2017 USD ($) $ / shares shares	Jun. 30, 2016 USD ($) shares		Sep. 30, 2016 USD ($)
Business Acquisition [Line Items]
Weighted average useful life			5 years
Total consideration			$ 1,900,000
Payment at closing			1,600,000
Measurement period adjustment											$ 5,600,000
Warrants outstanding (in shares) | shares						50,025,000					50,025,000
Founders Shares
Business Acquisition [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares) | shares						12,476,250		12,476,250			12,476,250	12,476,250
PSUs
Business Acquisition [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares) | shares						1,567,000		1,547,500			1,567,000	1,547,500
Warrant
Business Acquisition [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares) | shares						25,012,500					25,012,500
RSU
Business Acquisition [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares) | shares						24,500					24,500
Other Intangible Assets
Business Acquisition [Line Items]
Total consideration				$ 8,500,000
Successor
Business Acquisition [Line Items]
Cash paid for business acquisition											$ 63,500,000	$ 360,600,000	[1]
Transaction related costs						$ 200,000		$ 15,900,000	[1]		1,300,000	18,000,000	[1]
Change in fair value of contingent consideration obligations						(800,000)		(2,300,000)	[1]		$ 19,800,000	(2,300,000)	[1]
Predecessor
Business Acquisition [Line Items]
Cash paid for business acquisition										$ 0
Transaction related costs					$ 26,100,000					33,400,000
Change in fair value of contingent consideration obligations					0					0
Non-compete agreements | Minimum
Business Acquisition [Line Items]
Weighted average useful life											3 years
Non-compete agreements | Maximum
Business Acquisition [Line Items]
Weighted average useful life											10 years
Customer Lists
Business Acquisition [Line Items]
Intangible assets acquired			$ 1,100,000
Ultra Chem
Business Acquisition [Line Items]
Cash paid for business acquisition	$ 56,800,000
Cash acquired from acquisition	500,000
Purchase price held in escrow	10,700,000
Working capital adjustment held in escrow	1,000,000
Indemnification obligations held in escrow	$ 9,700,000
Maximum holding period in escrow	5 years
Contingent consideration	$ 0
Transaction related costs						300,000					$ 1,200,000
Reduction in gross receivables acquired											800,000
Increase (decrease) in inventory											1,200,000
Sales and operating revenue from acquiree						17,100,000					17,100,000
Net income from acquiree						200,000					200,000
Ultra Chem | Customer-related intangible
Business Acquisition [Line Items]
Intangible asset, amortization period	10 years
Finite-lived intangible assets	$ 22,000,000
Ultra Chem | Trade names
Business Acquisition [Line Items]
Intangible asset, amortization period	2 years
Finite-lived intangible assets	$ 300,000
Ultra Chem | Non-compete agreements
Business Acquisition [Line Items]
Intangible asset, amortization period	3 years
Finite-lived intangible assets	$ 3,700,000
Ultra Chem | Transaction Costs
Business Acquisition [Line Items]
Transaction related costs						300,000					500,000
Ultra Chem | Selling, general and administrative expenses
Business Acquisition [Line Items]
Transaction related costs											700,000
Ultra Chem | ABL Facility
Business Acquisition [Line Items]
Borrowings used for acquisition	$ 58,000,000
Nexeo Solutions Inc.
Business Acquisition [Line Items]
Transaction related costs						(100,000)					800,000
Increase (decrease) in inventory											$ (600,000)
Total consideration		$ 802,700,000
Payment at closing		$ 424,900,000
Number of mergers (in merger) | merger		2
Contingent consideration - Fair value of Deferred Cash Consideration		$ 45,400,000
Payment by the Company to Selling Equityholders of percentage of net cash tax savings											85.00%
Percentage of net cash tax savings retained by the Company											15.00%
Change in fair value of contingent consideration obligations						3,600,000	$ 2,000,000
Contingent consideration - Fair value of TRA		89,800,000
Undiscounted cash flows associated with the TRA liability		$ 215,000,000
Expected Benefit period of TRA		20 years
Decrease in property, plant and equipment											$ 100,000
Decrease in accounts payable											2,100,000
Increase in other current assets											200,000
Increase in deferred tax liabilities											400,000
Accounts receivable fair value adjustment		$ 4,100,000
Inventory fair value step up														$ 13,800,000
Number of real estate properties (in location) | location		42
Number of leased locations (in location) | location		11
Property, plant and equipment fair value adjustment		$ 96,000,000
Expected tax deductible goodwill amount						$ 253,400,000					$ 253,400,000
Nexeo Solutions Inc. | Successor
Business Acquisition [Line Items]
Transaction related costs								$ 15,900,000				$ 18,000,000
Nexeo Solutions Inc. | Predecessor
Business Acquisition [Line Items]
Transaction related costs					$ 26,100,000					$ 33,400,000
Nexeo Solutions Inc. | Selling Equityholders
Business Acquisition [Line Items]
Excess shares (in shares) | shares						5,178,642					5,178,642
Number of trading days to meet condition											20 days
Number of consecutive trading days											30 days
Share price (USD per share) | $ / shares						$ 15.00					$ 15.00
Number of days to elect excess shares provision											5 days
Nexeo Solutions Inc. | Customer-related intangible
Business Acquisition [Line Items]
Intangible asset, amortization period		12 years
Finite-lived intangible assets		$ 201,000,000
Nexeo Solutions Inc. | Trade names
Business Acquisition [Line Items]
Intangible asset, amortization period		4 years
Finite-lived intangible assets		$ 21,000,000
Nexeo Solutions Inc. | Below-market leases
Business Acquisition [Line Items]
Finite-lived intangible assets		$ 700,000
Nexeo Solutions Inc. | Below-market leases | Minimum
Business Acquisition [Line Items]
Lease term		1 year
Nexeo Solutions Inc. | Below-market leases | Maximum
Business Acquisition [Line Items]
Lease term		7 years
Other Intangible Assets
Business Acquisition [Line Items]
Payment for intangible assets				5,100,000
Recognized intangible assets				$ 8,500,000
Other Intangible Assets | Minimum
Business Acquisition [Line Items]
Weighted average useful life				10 years
Other Intangible Assets | Maximum
Business Acquisition [Line Items]
Weighted average useful life				13 years

[1] The three and nine months ended June 30, 2016 include 22 days of the acquired business’ operating activities as a result of the consummation of the Business Combination on June 9, 2016.