Commitments and Contingencies (Details) - USD ($)	Mar. 31, 2017	Sep. 30, 2016
Loss Contingencies [Line Items]
Purchase obligations for rest of fiscal year	$ 128,303,000
Purchase obligations for year two	5,116,000
Purchase obligations thereafter	849,000
Special Products Claims and Other Product Liabilities | Minimum
Loss Contingencies [Line Items]
Probable losses	3,000,000
Special Products Claims and Other Product Liabilities | Maximum
Loss Contingencies [Line Items]
Probable losses	10,000,000
Special Products Claims
Loss Contingencies [Line Items]
Product liability	3,593,000	$ 3,273,000
Other Product Liability
Loss Contingencies [Line Items]
Product liability	1,878,000	$ 1,678,000
Antidumping Duty, Malleable Iron Pipe Fittings from China
Loss Contingencies [Line Items]
Product liability	$ 7,501,000