The Business and Summary of Significant Accounting Policies - Narrative (Details) - USD ($) $ in Thousands |
3 Months Ended | ||
---|---|---|---|
Mar. 31, 2018 |
Mar. 31, 2017 |
Sep. 30, 2016 |
|
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items] | |||
Unrealized loss on equity investment | $ 134 | $ 0 | |
Unrealized loss on investments, net | 103 | (331) | |
Common stock of U.S. corporation | Quoted Prices in Active Markets for Identical Assets (Level 1) | |||
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items] | |||
Convertible preferred stock, shares issued upon conversion (in shares) | 1,071,429 | ||
Unrealized loss on equity investment | $ 100 | ||
Unrealized loss on investments, net | $ 600 |