Commitments and Contingent Liabilities (Details) $ in Thousands	Jun. 30, 2016 USD ($)
Loss Contingencies [Line Items]
Irrevocable letters of credit outstanding	$ 8,738
Letters of Credit Outstanding as Collateral for Janesville lease	5,000
Letters of credit outstanding for insurance reserve requirements of workers' compensation insurance carriers	1,538
Forward Contracts
Loss Contingencies [Line Items]
Letters of credit outstanding as collateral for commodity hedges	$ 1,100