Reclassification Out of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		May 31, 2016	May 31, 2015	May 31, 2016	May 31, 2015
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Net of Tax	[1]	$ (101,591)	$ (73,801)	$ (83,460)	$ (16,691)
Other comprehensive income (loss) before reclassifications	[1]	8,155	(7,786)	(11,864)	(65,892)
Amounts reclassified to earnings	[1]	421	429	1,586	1,364
Other comprehensive income (loss)	[1]	8,576	(7,357)	(10,278)	(64,528)
Less: comprehensive income (loss) attributable to noncontrolling interests	[1]	129	(61)	(594)	(122)
Net current period other comprehensive income (loss) attributable to A. Schulman, Inc.	[1]	8,447	(7,296)	(9,684)	(64,406)
Accumulated Other Comprehensive Income (Loss), Net of Tax	[1]	(93,144)	(81,097)	(93,144)	(81,097)
Accumulated Translation Adjustment [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Net of Tax	[1]	(68,858)	(35,259)	(49,562)	22,786
Other comprehensive income (loss) before reclassifications	[1]	8,155	(7,786)	(11,864)	(65,892)
Amounts reclassified to earnings	[1]	0	0	0	0
Other comprehensive income (loss)	[1]	8,155	(7,786)	(11,864)	(65,892)
Less: comprehensive income (loss) attributable to noncontrolling interests	[1]	129	(61)	(594)	(122)
Net current period other comprehensive income (loss) attributable to A. Schulman, Inc.	[1]	8,026	(7,725)	(11,270)	(65,770)
Accumulated Other Comprehensive Income (Loss), Net of Tax	[1]	(60,832)	(42,984)	(60,832)	(42,984)
Accumulated Defined Benefit Plans Adjustment [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Net of Tax	[1]	(32,733)	(38,542)	(33,898)	(39,477)
Other comprehensive income (loss) before reclassifications	[1]	0	0	0	0
Amounts reclassified to earnings	[1],[2]	421	429	1,586	1,364
Other comprehensive income (loss)	[1]	421	429	1,586	1,364
Less: comprehensive income (loss) attributable to noncontrolling interests	[1]	0	0	0	0
Net current period other comprehensive income (loss) attributable to A. Schulman, Inc.	[1]	421	429	1,586	1,364
Accumulated Other Comprehensive Income (Loss), Net of Tax	[1]	$ (32,312)	$ (38,113)	$ (32,312)	$ (38,113)

[1] (1) All amounts presented are net of tax. All tax amounts are related to pension and other retiree benefits.

[2] (2) Amounts represent amortization of net actuarial loss and prior service costs and are reclassified from accumulated other comprehensive income into cost of sales and selling, general & administrative expenses on the consolidated statements of operations. These components are included in the computation of net periodic pension cost. Refer to Note 7 of this Form 10-Q for further details.