XML 202 R60.htm IDEA: XBRL DOCUMENT
v3.20.2

Investments - Additional Information (Detail) - USD ($) | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2020 | Sep. 30, 2019 | Sep. 30, 2020 | Sep. 30, 2019
Investments, Debt and Equity Securities [Abstract] |  |  |  |
Unrealized gain (loss), net of other expenses | $ 600,000 | $ (100,000) | $ 400,000 | $ 1,000,000.0

X
- References No definition available. + Details
Name: | us-gaap_InvestmentsDebtAndEquitySecuritiesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of unrealized holding gain (loss) recognized in the income statement for investments in debt and equity securities and other forms of securities that provide ownership interests classified as trading. + References No definition available. + Details
Name: | us-gaap_TradingSecuritiesUnrealizedHoldingGainLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration