Airgas Transaction (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended	6 Months Ended
Mar. 31, 2011	Mar. 31, 2011
Airgas Transaction [Abstract]
Net loss on Airgas transaction	$ 5.0	$ 48.5
Transaction costs incurred during period, after-tax	4.4	31.6
Transaction costs incurred during period, after-tax, per share	$ 0.02	$ 0.14
Payments of acquisition-related costs		$ 153.8

Costs incurred in connection with an unsolicited tender offer (one where the entity being sought has not requested the offer) stated on a per share basis. These would include the amortization of fees related to the term loan credit facility that would fund the acquisition and other acquisition related costs of the acquirer as well. A tender offer is a broad solicitation by an entity or a third party to purchase a substantial percentage of another entity's shares or units for a limited period of time. The offer is at a fixed price, usually at a premium over the current market price, and may be contingent on shareholders' tendering a fixed number of their shares or units.

No definition available.

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Period Type:	duration