Annual report pursuant to Section 13 and 15(d)

Organization and Significant Accounting Policies - Option Valuation Activity (Details)

v3.19.1
Organization and Significant Accounting Policies - Option Valuation Activity (Details) - USD ($)
$ in Thousands
12 Months Ended
Mar. 31, 2019
Mar. 31, 2018
Mar. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Change in value of TOKIN options $ 0 $ 0 $ 10,700
Recurring | NEC TOKIN Corporation | Level 3 | Put Option      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Change in value of TOKIN options   $ 10,700