Fair Value Measurements Fair Value Hierarchy (Details) - USD ($) $ in Thousands | Jun. 30, 2018 | Mar. 31, 2018 |
US Government Agencies Debt Securities [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Assets, Fair Value Disclosure | | | $ 1,999 |
US Government Agencies Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Assets, Fair Value Disclosure | | | 1,999 |
Cash Equivalents [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Assets, Fair Value Disclosure | | $ 49,046 | 49,749 |
Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Assets, Fair Value Disclosure | | 41,055 | 44,252 |
Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Assets, Fair Value Disclosure | | 7,991 | 5,497 |
Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Assets, Fair Value Disclosure | | 0 | 0 |
Cash Equivalents [Member] | Money Market Instruments [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Assets, Fair Value Disclosure | | 41,055 | 41,752 |
Cash Equivalents [Member] | Money Market Instruments [Member] | Fair Value, Inputs, Level 1 [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Assets, Fair Value Disclosure | | 41,055 | 41,752 |
Cash Equivalents [Member] | US Treasury Securities [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Assets, Fair Value Disclosure | | | 2,500 |
Cash Equivalents [Member] | US Treasury Securities [Member] | Fair Value, Inputs, Level 1 [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Assets, Fair Value Disclosure | | | 2,500 |
Cash Equivalents [Member] | Commercial Paper [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Assets, Fair Value Disclosure | | 6,991 | 3,498 |
Cash Equivalents [Member] | Commercial Paper [Member] | Fair Value, Inputs, Level 1 [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Assets, Fair Value Disclosure | | | 0 |
Cash Equivalents [Member] | Commercial Paper [Member] | Fair Value, Inputs, Level 2 [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Assets, Fair Value Disclosure | | 6,991 | 3,498 |
Cash Equivalents [Member] | Corporate Bond Securities [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Assets, Fair Value Disclosure | | 1,000 | |
Cash Equivalents [Member] | Corporate Bond Securities [Member] | Fair Value, Inputs, Level 2 [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Assets, Fair Value Disclosure | | 1,000 | |
Short-term Investments [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Assets, Fair Value Disclosure | | 55,026 | 47,121 |
Short-term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Assets, Fair Value Disclosure | | 10,481 | 10,458 |
Short-term Investments [Member] | Fair Value, Inputs, Level 2 [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Assets, Fair Value Disclosure | | 44,545 | 36,663 |
Short-term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Assets, Fair Value Disclosure | | 0 | 0 |
Short-term Investments [Member] | US Treasury Securities [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Assets, Fair Value Disclosure | | 10,481 | 10,458 |
Short-term Investments [Member] | US Treasury Securities [Member] | Fair Value, Inputs, Level 1 [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Assets, Fair Value Disclosure | | 10,481 | 10,458 |
Short-term Investments [Member] | US Treasury Securities [Member] | Fair Value, Inputs, Level 2 [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Assets, Fair Value Disclosure | | 0 | 0 |
Short-term Investments [Member] | US Treasury Securities [Member] | Fair Value, Inputs, Level 3 [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Assets, Fair Value Disclosure | | 0 | 0 |
Short-term Investments [Member] | Commercial Paper [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Assets, Fair Value Disclosure | | 34,041 | 25,913 |
Short-term Investments [Member] | Commercial Paper [Member] | Fair Value, Inputs, Level 1 [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Assets, Fair Value Disclosure | | 0 | 0 |
Short-term Investments [Member] | Commercial Paper [Member] | Fair Value, Inputs, Level 2 [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Assets, Fair Value Disclosure | | 34,041 | 25,913 |
Short-term Investments [Member] | Commercial Paper [Member] | Fair Value, Inputs, Level 3 [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Assets, Fair Value Disclosure | | 0 | 0 |
Short-term Investments [Member] | Corporate Bond Securities [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Assets, Fair Value Disclosure | | 10,504 | 10,750 |
Short-term Investments [Member] | Corporate Bond Securities [Member] | Fair Value, Inputs, Level 1 [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Assets, Fair Value Disclosure | | 0 | 0 |
Short-term Investments [Member] | Corporate Bond Securities [Member] | Fair Value, Inputs, Level 2 [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Assets, Fair Value Disclosure | | 10,504 | 10,750 |
Short-term Investments [Member] | Corporate Bond Securities [Member] | Fair Value, Inputs, Level 3 [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Assets, Fair Value Disclosure | | 0 | |
Foreign Exchange Forward [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Obligations, Fair Value Disclosure | | | 6 |
Foreign Exchange Forward [Member] | Forward Contracts [Member] | Fair Value, Inputs, Level 2 [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Obligations, Fair Value Disclosure | | | 6 |
Foreign Exchange Forward [Member] | Forward Contracts [Member] | Fair Value, Measurements, Recurring [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Obligations, Fair Value Disclosure | | 196 | |
Foreign Exchange Forward [Member] | Forward Contracts [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Obligations, Fair Value Disclosure | | 196 | |
Deferred Compensation Plan Asset [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Deferred Compensation Plan Assets | [1] | 2,331 | 2,048 |
Deferred Compensation Plan Asset [Member] | Fair Value, Inputs, Level 1 [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Deferred Compensation Plan Assets | [1] | 2,331 | 2,048 |
Deferred Compensation Plan Asset [Member] | Fair Value, Inputs, Level 2 [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Deferred Compensation Plan Assets | [1] | 0 | 0 |
Deferred Compensation Plan Asset [Member] | Fair Value, Inputs, Level 3 [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Deferred Compensation Plan Assets | [1] | 0 | 0 |
Deferred Compensation Plan Asset [Member] | Exchange Traded Funds [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Deferred Compensation Plan Assets | | 2,123 | 1,841 |
Deferred Compensation Plan Asset [Member] | Exchange Traded Funds [Member] | Fair Value, Inputs, Level 1 [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Deferred Compensation Plan Assets | [1] | 2,123 | 1,841 |
Deferred Compensation Plan Asset [Member] | Exchange Traded Funds [Member] | Fair Value, Inputs, Level 2 [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Deferred Compensation Plan Assets | [1] | 0 | 0 |
Deferred Compensation Plan Asset [Member] | Exchange Traded Funds [Member] | Fair Value, Inputs, Level 3 [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Deferred Compensation Plan Assets | [1] | 0 | 0 |
Deferred Compensation Plan Asset [Member] | Money Market Funds [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Deferred Compensation Plan Assets | [1] | 208 | 207 |
Deferred Compensation Plan Asset [Member] | Money Market Funds [Member] | Fair Value, Inputs, Level 1 [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Deferred Compensation Plan Assets | [1] | 208 | 207 |
Deferred Compensation Plan Asset [Member] | Money Market Funds [Member] | Fair Value, Inputs, Level 2 [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Deferred Compensation Plan Assets | [1] | 0 | 0 |
Deferred Compensation Plan Asset [Member] | Money Market Funds [Member] | Fair Value, Inputs, Level 3 [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Deferred Compensation Plan Assets | [1] | 0 | 0 |
Japan, Yen | Foreign Exchange Forward [Member] | Forward Contracts [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Assets, Fair Value Disclosure | | 66 | |
Obligations, Fair Value Disclosure | | | 23 |
Japan, Yen | Foreign Exchange Forward [Member] | Forward Contracts [Member] | Fair Value, Inputs, Level 2 [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Assets, Fair Value Disclosure | | 66 | |
Obligations, Fair Value Disclosure | | | 23 |
Taiwan, New Dollars | Foreign Exchange Forward [Member] | Forward Contracts [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Assets, Fair Value Disclosure | | | 3 |
Obligations, Fair Value Disclosure | | 57 | |
Taiwan, New Dollars | Foreign Exchange Forward [Member] | Forward Contracts [Member] | Fair Value, Inputs, Level 2 [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Assets, Fair Value Disclosure | | | 3 |
Obligations, Fair Value Disclosure | | 57 | |
Korea (South), Won | Foreign Exchange Forward [Member] | Forward Contracts [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Obligations, Fair Value Disclosure | | 94 | 12 |
Korea (South), Won | Foreign Exchange Forward [Member] | Forward Contracts [Member] | Fair Value, Inputs, Level 2 [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Obligations, Fair Value Disclosure | | 94 | 12 |
Euro Member Countries, Euro | Foreign Exchange Forward [Member] | Forward Contracts [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Assets, Fair Value Disclosure | | 3 | 7 |
Euro Member Countries, Euro | Foreign Exchange Forward [Member] | Forward Contracts [Member] | Fair Value, Inputs, Level 2 [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Assets, Fair Value Disclosure | | 3 | 7 |
United Kingdom, Pounds | Forward Contracts [Member] | Fair Value, Inputs, Level 2 [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Assets, Fair Value Disclosure | | | 49 |
United Kingdom, Pounds | Foreign Exchange Forward [Member] | Forward Contracts [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Assets, Fair Value Disclosure | | | 49 |
Obligations, Fair Value Disclosure | | 29 | |
United Kingdom, Pounds | Foreign Exchange Forward [Member] | Forward Contracts [Member] | Fair Value, Inputs, Level 2 [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Obligations, Fair Value Disclosure | | 29 | |
China, Yuan Renminbi | Foreign Exchange Forward [Member] | Forward Contracts [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Obligations, Fair Value Disclosure | | 91 | 29 |
China, Yuan Renminbi | Foreign Exchange Forward [Member] | Forward Contracts [Member] | Fair Value, Inputs, Level 2 [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Obligations, Fair Value Disclosure | | 91 | 29 |
Singapore, Dollars | Foreign Exchange Forward [Member] | Forward Contracts [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Obligations, Fair Value Disclosure | | | 1 |
Singapore, Dollars | Foreign Exchange Forward [Member] | Forward Contracts [Member] | Fair Value, Inputs, Level 2 [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Obligations, Fair Value Disclosure | | | $ 1 |
Singapore, Dollars | Foreign Exchange Forward [Member] | Forward Contracts [Member] | Fair Value, Measurements, Recurring [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Assets, Fair Value Disclosure | | 6 | |
Singapore, Dollars | Foreign Exchange Forward [Member] | Forward Contracts [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Assets, Fair Value Disclosure | | $ 6 | |
| |
[1] | *These investments represent assets held in trust for the deferred compensation plan | |