Acquisition (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				6 Months Ended
	Dec. 31, 2011	Dec. 31, 2011 Echologics Engineering, Inc. [Member]	Sep. 30, 2011 Echologics Engineering, Inc. [Member]	Dec. 14, 2010 Echologics Engineering, Inc. [Member]	Mar. 31, 2012 Trade Names And Trade Marks[Member] Echologics Engineering, Inc. [Member]	Mar. 31, 2011 Technology [Member] Echologics Engineering, Inc. [Member] years
Business Acquisition [Line Items]
Cash paid for acquisition				$ 7.9
Escrow deposit related to seller indemnifications				1.5
Reduction of Indemnification	0.5
Goodwill		0	0.5
Funds released from escrow	0.5
Identifiable intangible assets, indefinite lived					0.6
Identifiable intangible assets, finite lived						$ 6.7
Identifiable intangible assets, estimated useful life (in years)						15