Fair Value Measurements Schedule of Fair Value Assets and Liabilities (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Sep. 30, 2018	Mar. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Non-qualified deferred compensation asset		$ 7,172
Non-qualified deferred compensation liability	$ (5,378)	(4,296)
Derivative contracts asset	7,469
Derivative contracts liability	(20)
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Non-qualified deferred compensation asset	7,542	7,172
Non-qualified deferred compensation liability	(5,378)	(4,296)
Designated Derivative Contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative contracts asset	6,722	950
Designated Derivative Contracts | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative contracts asset	6,722	950
Non-Designated Derivative Contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative contracts asset	747
Derivative contracts liability	(20)	(10)
Non-Designated Derivative Contracts | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative contracts asset	747
Derivative contracts liability	(20)	(10)
Derivatives designated as cash flow hedges | Designated Derivative Contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative contracts liability	$ 0	(143)
Derivatives designated as cash flow hedges | Designated Derivative Contracts | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative contracts liability		$ (143)