Net Income per Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	May 31, 2012	May 31, 2011	May 31, 2012	May 31, 2011
Numerator:
Net income from continuing operations attributable to Robbins & Myers, Inc.	$ 44,227	$ 18,920	$ 117,600	$ 44,951
Denominator:
Basic weighted average shares	43,097	45,616	44,628	39,449
Effect of dilutive options and restricted shares/units	194	349	209	363
Diluted weighted average shares	43,291	45,965	44,837	39,812
Basic net income per share from continuing operations	$ 1.03	$ 0.41	$ 2.64	$ 1.14
Diluted net income per share from continuing operations	$ 1.02	$ 0.41	$ 2.62	$ 1.13
Anti-dilutive options (excluded from diluted net income per share computations)	32	45	32	207