Fair Value of Financial Instruments (Details) - Fair Value Measurements Recurring $ in Thousands	Sep. 30, 2018 USD ($)
Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Assets at Fair Value	$ 2,870
Level 1 | Fixed Income Funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Assets at Fair Value	864
Level 1 | Stock Index Funds | Small Cap
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Assets at Fair Value	283
Level 1 | Stock Index Funds | Mid Cap
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Assets at Fair Value	285
Level 1 | Stock Index Funds | Large Cap
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Assets at Fair Value	575
Level 1 | Stock Index Funds | International
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Assets at Fair Value	863
Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Assets at Fair Value	186
Level 2 | Mexican Peso Forward Contracts
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Assets at Fair Value	$ 186