Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Convertible special stock, no par value [Member]	Common Stock ($1 par value) [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Noncontrolling Interest [Member]
Balance at Aug. 31, 2012	$ 507,689	$ 0	$ 47,958	$ 259,253	$ (5,921)	$ 571,205	$ (371,099)	$ 6,293
Comprehensive income (loss)	33,776				6,603	26,099		1,074
Cash dividends paid	(22,934)					(22,934)
Purchase of treasury stock	(8,091)						(8,091)
Issuance of treasury stock	356			93			263
Stock options exercised	1,205		64	1,141
Restricted stock issued, net of forfeitures	0		93	(93)
Redemption of common stock to cover tax withholdings	(396)		(21)	(375)
Amortization of restricted stock	3,139			3,139
Balance at Aug. 31, 2013	514,744	0	48,094	263,158	682	574,370	(378,927)	7,367
Comprehensive income (loss)	39,532				(17,373)	56,193		712
Cash dividends paid	(23,665)					(23,665)
Noncontrolling interests' contributions (distributions)	600							600
Change in ownership interest	0			(729)				729
Purchase of treasury stock	(1,116)						(1,116)
Issuance of treasury stock	254			105			149
Stock options exercised	233		13	220
Restricted stock issued, net of forfeitures	0		88	(88)
Redemption of common stock to cover tax withholdings	(361)		(10)	(351)
Amortization of restricted stock	6,230			6,230
Balance at Aug. 31, 2014	536,451	0	48,185	268,545	(16,691)	606,898	(379,894)	9,408
Comprehensive income (loss)	(39,149)				(66,769)	26,629		991
Cash dividends paid	(24,024)					(24,024)
Cash Dividends Paid on Convertible Special Stock	(1,813)					(1,813)
Noncontrolling interests' contributions (distributions)	(1,750)							(1,750)
Purchase of treasury stock	(3,335)						(3,335)
Issuance of treasury stock	225			117			108
Stock options exercised	64		3	61
Restricted stock issued, net of forfeitures	0		331	(331)
Redemption of common stock to cover tax withholdings	(4,999)		(150)	(4,849)
Amortization of restricted stock	10,270			10,270
Balance at Aug. 31, 2015	592,735	120,289	$ 48,369	274,319	$ (83,460)	$ 607,690	$ (383,121)	$ 8,649
Tax windfall (shortfall) related to share- based incentive compensation	506			$ 506
Issuance of convertible special stock, net of Issuance costs	$ 120,289	$ 120,289