Fair Value Measurement (Details) - USD ($)	9 Months Ended
	May 31, 2016	Aug. 31, 2015
Assets recorded at fair value:
Foreign exchange forward contracts	$ 952,000	$ 1,818,000
Liabilities recorded at fair value:
Foreign exchange forward contracts	1,779,000	1,576,000
Liabilities not recorded at fair value:
Long-term fixed-rate debt	375,236,000	374,299,000
Contract value of foreign exchange forward contracts outstanding	112,600,000	161,500,000
Fair Value Hedges, Net	0	0
Senior notes, 6.875%, due June 2023	375,000,000	375,000,000
Fair Value, Transfers Between Levels, Amount	0
Assets, Fair Value Disclosure, Nonrecurring	0
Liabilities, Fair Value Disclosure, Nonrecurring	0
Fair Value, Inputs, Level 1 [Member]
Assets recorded at fair value:
Foreign exchange forward contracts	0	0
Liabilities recorded at fair value:
Foreign exchange forward contracts	0	0
Liabilities not recorded at fair value:
Long-term fixed-rate debt	0	0
Fair Value, Inputs, Level 2 [Member]
Assets recorded at fair value:
Foreign exchange forward contracts	952,000	1,818,000
Liabilities recorded at fair value:
Foreign exchange forward contracts	1,779,000	1,576,000
Liabilities not recorded at fair value:
Long-term fixed-rate debt	375,236,000	374,299,000
Fair Value, Inputs, Level 3 [Member]
Assets recorded at fair value:
Foreign exchange forward contracts	0	0
Liabilities recorded at fair value:
Foreign exchange forward contracts	0	0
Liabilities not recorded at fair value:
Long-term fixed-rate debt	$ 0	$ 0