Unaudited Quarterly Results (Details 2) (USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended
	Sep. 30, 2012	Sep. 30, 2012
Undefinitization Contracts | Defense
Revenues	$ 7.8	$ 7.8
Revenues, net of tax	5.0
Income (Loss), Before Taxes | Valuation of Performance Shares
Correction of misstatement	7.0
Net Income [Member] | Valuation of Performance Shares
Correction of misstatement	4.5
Selling, General and Administrative Expenses
Curtailment of pension and other postretirement benefit plans	3.4
Selling, General and Administrative Expenses, Net of Tax
Curtailment of pension and other postretirement benefit plans	2.2
Income Tax Expense (Benefit) | Deferred Tax Assets
Correction of misstatement	$ (5.7)