Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	3 Months Ended
	Nov. 30, 2016	Nov. 30, 2015
Increase (Decrease) In Accumulated Other Comprehensive Loss [Roll Forward}
Balance - September 1 (Beginning of period)	$ 501,432	$ 538,551
Total other comprehensive income (loss), net of tax	(1,099)	(728)
Balance - November 30 (End of period)	494,067	524,448
Foreign Currency Translation Adjustments
Increase (Decrease) In Accumulated Other Comprehensive Loss [Roll Forward}
Balance - September 1 (Beginning of period)	(34,539)	(34,009)
Other comprehensive income (loss) before reclassifications	(1,034)	(1,009)
Income tax expense	0	0
Other comprehensive loss before reclassifications, net of tax	(1,034)	(1,009)
Amounts reclassified from accumulated other comprehensive loss	0	0
Income tax benefit	0	0
Amounts reclassified from accumulated other comprehensive loss, net of tax	0	0
Total other comprehensive income (loss), net of tax	(1,034)	(1,009)
Balance - November 30 (End of period)	(35,573)	(35,018)
Pension Obligations, net
Increase (Decrease) In Accumulated Other Comprehensive Loss [Roll Forward}
Balance - September 1 (Beginning of period)	(5,576)	(4,273)
Other comprehensive income (loss) before reclassifications	49	0
Income tax expense	(194)	0
Other comprehensive loss before reclassifications, net of tax	(145)	0
Amounts reclassified from accumulated other comprehensive loss	125	64
Income tax benefit	(45)	(23)
Amounts reclassified from accumulated other comprehensive loss, net of tax	80	41
Total other comprehensive income (loss), net of tax	(65)	41
Balance - November 30 (End of period)	(5,641)	(4,232)
Net Unrealized Gain (Loss) on Cash Flow Hedges
Increase (Decrease) In Accumulated Other Comprehensive Loss [Roll Forward}
Balance - September 1 (Beginning of period)		(240)
Other comprehensive income (loss) before reclassifications		0
Income tax expense		0
Other comprehensive loss before reclassifications, net of tax		0
Amounts reclassified from accumulated other comprehensive loss		312
Income tax benefit		(72)
Amounts reclassified from accumulated other comprehensive loss, net of tax		240
Total other comprehensive income (loss), net of tax		240
Balance - November 30 (End of period)		0
AOCI Attributable to Parent
Increase (Decrease) In Accumulated Other Comprehensive Loss [Roll Forward}
Balance - September 1 (Beginning of period)	(40,115)	(38,522)
Other comprehensive income (loss) before reclassifications	(985)	(1,009)
Income tax expense	(194)	0
Other comprehensive loss before reclassifications, net of tax	(1,179)	(1,009)
Amounts reclassified from accumulated other comprehensive loss	125	376
Income tax benefit	(45)	(95)
Amounts reclassified from accumulated other comprehensive loss, net of tax	80	281
Total other comprehensive income (loss), net of tax	(1,099)	(728)
Balance - November 30 (End of period)	$ (41,214)	$ (39,250)