Significant Accounting Policies (Segment Reporting Revenue Percentage) (Details)	3 Months Ended		6 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Mar. 31, 2012	Mar. 31, 2011
Core Segment [Member]
Segment Reporting Information [Line Items]
Revenue, by segment	65.00%	63.00%	65.00%	64.00%
Performance Segment [Member]
Segment Reporting Information [Line Items]
Revenue, by segment	28.00%	31.00%	28.00%	30.00%
New Business Segment [Member]
Segment Reporting Information [Line Items]
Revenue, by segment	4.00%	4.00%	4.00%	4.00%
Specialty Fluids Segment [Member]
Segment Reporting Information [Line Items]
Revenue, by segment	3.00%	2.00%	3.00%	2.00%