Fair Value Measurements Narrative (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)
Other Assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Non-qualified deferred compensation asset	7,542
Other Accrued Liabilities, Current
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Accrued deferred compensation liability	1,505
Other Long Term Liabilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other long term liabilities	$ 3,873