Aclara Divestiture (Narrative) (Details) - USD ($) $ in Thousands	1 Months Ended		3 Months Ended								12 Months Ended
	Jun. 15, 2015	Mar. 28, 2014	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Net sales			$ 153,612	$ 134,191	$ 128,941	$ 120,547	$ 151,413	$ 130,495	$ 124,762	$ 124,450	$ 537,291	$ 531,120	$ 490,079
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax, Total											776	(52,061)	0
Discontinued Operation Loss on Disposal of Discontinued Operation												15,600
Aclara Technologies LLC [Member]
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, before Tax											$ 1,200	(48,200)	(62,100)
Net sales												129,600	184,500
Proceeds from Divestiture of Businesses, Net of Cash Divested, Total		$ 135,000
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax, Total												$ 63,800	$ 48,000
Repayments of Other Debt	$ 2,300