Long-Term Debt Outstanding Revolving Loans (Details) - Revolving credit facility [Member] € in Thousands, £ in Thousands, CAD in Thousands, $ in Thousands	Sep. 30, 2017 GBP (£)	Sep. 30, 2017 EUR (€)	Sep. 30, 2017 USD ($)	Sep. 30, 2017 CAD
British Pound (Swingline Loan) [Member]
Line of Credit Facility [Line Items]
Long-term Debt, Gross	£ 5,500		$ 7,366
Debt Instrument, Interest Rate, Stated Percentage	1.97%	1.97%	1.97%	1.97%
British Pound Revolving Loan [Member]
Line of Credit Facility [Line Items]
Long-term Debt, Gross	£ 134,000		$ 179,466
Debt Instrument, Interest Rate, Stated Percentage	2.00%	2.00%	2.00%	2.00%
Canadian Dollar Revolving Loan [Member]
Line of Credit Facility [Line Items]
Long-term Debt, Gross			$ 5,608	CAD 7,000
Debt Instrument, Interest Rate, Stated Percentage	3.07%	3.07%	3.07%	3.07%
Euro Revolving Loan [Member]
Line of Credit Facility [Line Items]
Long-term Debt, Gross		€ 28,400	$ 33,520
Debt Instrument, Interest Rate, Stated Percentage	1.75%	1.75%	1.75%	1.75%