Short-Term Borrowings and Long-Term Debt Interest Rate Swap - Revolving Credit Facility (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Sep. 30, 2016
Line of Credit Facility [Line Items]
Derivative, Notional Amount	$ 20,253
Derivative, Term of Contract	4 years 245 days
Interest Rate Swap [Member]
Line of Credit Facility [Line Items]
Derivative, Fixed Interest Rate			1.35%
Derivative, Notional Amount	$ 20,253
Interest Rate Swap [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Derivative, Fixed Interest Rate			2.30%
Derivative, Notional Amount			$ 500,000
Derivative, Term of Contract	4 years 245 days
Derivative Liability, Not Subject to Master Netting Arrangement		$ (4,369)
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax		(2,683)
Deferred Tax Assets, Hedging Transactions		1,686
Derivative, Loss on Derivative		$ (527)