Commitments and Contingencies - Other Disclosures (Details) (USD $) In Millions, unless otherwise specified	1 Months Ended	12 Months Ended						0 Months Ended
	Mar. 31, 2012	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012	May 31, 2014	May 31, 2013	Apr. 30, 2013	Sep. 23, 2014 Sumitomo Electric Industires Ltd
Loss Contingencies [Line Items]
Operating leases, rent expense, net		$ 1.7	$ 2.3	$ 2.7
Credit adjusted risk-free rate, minimum		3.25%
Credit adjusted risk-free rate, maximum		5.78%
Asset Retirement Obligation, Liabilities Settled			0.1
Asset retirement obligation, accretion expense		0.2	0.2	0.2
Business combination, indemnification assets, range of outcomes, value (up to $3.4 million)		3.4
Business combination, indemnification duration, period taken into account for	2 years
Business combination, indemnification assets, amount as of acquisition date (up to $1.5 million)					1.5	1.5	1.5
Arbitration damages sought amount								$ 40.0