Goodwill and Other Intangible Assets - Future Amortization Expense (Details) $ in Thousands	Sep. 30, 2017 USD ($)
Estimate of the amount and classification of amortization expense for definite-lived intangible assets
Amortization Expense, 2018	$ 4,006
Amortization Expense, 2019	3,772
Amortization Expense, 2020	3,343
Amortization Expense, 2021	2,310
Amortization Expense, 2022	1,390
Operations Expense, 2018	23
Operations Expense, 2019	23
Operations Expense, 2020	23
Operations Expense, 2021	22
Operations Expense, 2022	$ 2