XML 46 R65.htm IDEA: XBRL DOCUMENT v3.20.1
Financial Derivatives - Additional Information (Detail) - USD ($)
3 Months Ended 12 Months Ended
Mar. 31, 2020
Dec. 31, 2019
Derivative Instruments And Hedging Activities Disclosure [Abstract]    
Maximum amount of loss due to credit risk $ 2,500,000 $ 3,600,000
Total net settlement amount asset positions 2,000,000.0 3,400,000
Total net settlement amount liability positions $ 200,000 $ 0