Quarterly Financial Highlights (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended																12 Months Ended
	Aug. 31, 2015		May. 31, 2015		Feb. 28, 2015		Nov. 30, 2014		Aug. 31, 2014		May. 31, 2014		Feb. 28, 2014		Nov. 30, 2013		Aug. 31, 2015		Aug. 31, 2014		Aug. 31, 2013
Net sales	$ 674,019		$ 560,858		$ 542,295		$ 615,053		$ 627,358		$ 645,735		$ 588,508		$ 585,397		$ 2,392,225		$ 2,446,998		$ 2,133,402
Gross profit	105,335		90,757		78,074		86,844		84,637		91,964		74,299		79,108		361,010		330,008		281,179
Income (loss) from continuing operations	24,014		(8,968)		(503)		13,388		15,164		19,347		6,648		12,631		27,931		53,790		33,999
Income (loss) from discontinued operations, net of tax	(47)		(18)		(58)		(10)		223		(23)		347		2,655		(133)		3,202		(6,671)
Net income (loss)	23,967		(8,986)		(561)		13,378		15,387		19,324		6,995		15,286		27,798		56,992		27,328
Noncontrolling interests	(279)		(343)		(327)		(220)		(215)		(233)		(136)		(215)		(1,169)		(799)		(1,229)
Net income (loss) attributable to A. Schulman, Inc.	23,688		(9,329)		(888)		13,158		$ 15,172		$ 19,091		$ 6,859		$ 15,071		26,629		56,193		26,099
Convertible special stock dividends	(1,875)		(563)		0		0										(2,438)
Net income (Loss) available to A. Schulman Inc. common stockholders	$ 21,813		$ (9,892)		$ (888)		$ 13,158										$ 24,191		$ 56,193		$ 26,099
Basic earnings per share available to A. Schulman, Inc. common stockholders
Income (loss) from continuing operations	$ 0.75		$ (0.34)	[1]	$ (0.03)	[1]	$ 0.45	[1]	$ 0.51	[2]	$ 0.66	[2]	$ 0.23	[2]	$ 0.43	[2]	$ 0.83		$ 1.82	[2]	$ 1.12
Income (loss) from discontinued operations	0		0.00	[1]	0.00	[1]	0.00	[1]	0.01	[2]	0.00	[2]	0.01	[2]	0.09	[2]	0.00		0.11	[2]	(0.23)
Net income (loss) available to A. Schulman, Inc. common stockholders	0.75		(0.34)	[1]	(0.03)	[1]	0.45	[1]	0.52	[2]	0.66	[2]	0.24	[2]	0.52	[2]	0.83		1.93	[2]	0.89
Diluted earnings per share available to A. Schulman, Inc. common stockholders
Income (loss) from continuing operations	0.75		(0.34)	[1]	(0.03)	[1]	0.45	[1]	0.51	[2]	0.65	[2]	0.22	[2]	0.43	[2]	0.83		1.80	[2]	1.12
Income (loss) from discontinued operations	(0.01)		0.00	[1]	0.00	[1]	0.00	[1]	0.01	[2]	0.00	[2]	0.01	[2]	0.09	[2]	(0.01)		0.11	[2]	(0.23)
Net income (loss) available to A. Schulman, Inc. common stockholders	$ 0.74		$ (0.34)	[1]	$ (0.03)	[1]	$ 0.45	[1]	$ 0.52	[2]	$ 0.65	[2]	$ 0.23	[2]	$ 0.52	[2]	$ 0.82		$ 1.91	[2]	$ 0.89
Certain items included in income from continuing operations, net of tax
Accelerated depreciation	$ 53	[3]	$ 29	[3]	$ 298	[3]	$ 0	[3]	$ 0	[4]	$ 0	[4]	$ 70	[4]	$ 107	[4]	$ 380	[3]	$ 177	[4]
Costs related to acquisitions	9,200	[5]	3,561	[5]	3,135	[5]	976	[5]	2,635	[6]	872	[6]	1,822	[6]	546	[6]	16,872	[5]	5,875	[6]
Acquisition related interest expense	1,190		19,134		0		0										20,324
Restructuring and related costs	6,927	[7]	4,793	[7]	3,260	[7]	4,096	[7]	1,463	[8]	1,840	[8]	2,513	[8]	3,340	[8]	19,076	[7]	9,156	[8]
CEO transition costs	0		0		6,167		0										6,167		0		$ 0
Inventory step-up	2,631	[9]	0	[9]	0	[9]	239	[9]	323	[10]	0	[10]	782	[10]	319	[10]	2,870	[9]	1,424	[10]
Gain on early extinguishment of debt	0		0		(863)		0										(863)
Total	$ 20,001		27,517		$ 11,997		$ 5,311		$ 4,421		$ 2,712		$ 5,187		$ 4,312		64,826		16,632
Bridge financing fees			$ 18,750														18,750		$ 0		$ 0
Write off of Deferred Debt Issuance Cost																	$ 1,500

[1] The sum of the four quarters does not equal the earnings per share amount calculated for the year due to rounding.

[2] The sum of the four quarters does not equal the earnings per share amount calculated for the year due to rounding.

[3] Relates to accelerated depreciation in the U.S., France and Brazil.

[4] Costs related to acquisitions include professional, legal and other expenses associated with the Perrite Group, Network Polymers, Inc., Prime Colorants and the Specialty Plastics acquisitions, along with other potential acquisitions.

[5] Costs related to acquisitions include professional, legal and other expenses associated with the Citadel acquisition, along with other potential acquisitions.

[6] Asset write-downs include charges primarily related to the write-down of the facility in Oyonnax, France.

[7] Restructuring and related costs include items such as employee severance charges, lease termination charges, curtailment gains/losses, other employee termination costs and charges related to the reorganization of the legal entity structure. Refer to Note 16 of this Form 10-K for further discussion.

[8] Restructuring and related costs include items such as employee severance charges, lease termination charges, curtailment gains/losses, other employee termination costs and charges related to the reorganization of the legal entity structure. Refer to Note 16 of this Form 10-K for further discussion

[9] Inventory step-up relates to the fiscal 2015 acquisition noted above.

[10] Inventory step-up relates to the fiscal 2014 acquisitions noted above.