Summary of Significant Accounting Policies Goodwill Impairment and Fair Value Analysis (Details) - Engineered Films [Member] $ in Thousands	Jul. 31, 2015 USD ($)
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Reporting Unit, Amount of Fair Value in Excess of Carrying Amount	$ 50,000
Reporting Unit, Percentage of Fair Value in Excess of Carrying Amount	40.00%
Engineered Films asset group [Domain]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Reporting Unit, Amount of Fair Value in Excess of Carrying Amount	$ 100,000
Reporting Unit, Percentage of Fair Value in Excess of Carrying Amount	150.00%