XML 58 R45.htm IDEA: XBRL DOCUMENT v3.19.1
Risk Management and Derivative Instruments - Additional Information (Detail)
3 Months Ended
Mar. 31, 2019
USD ($)
Derivative Instruments And Hedging Activities Disclosure [Abstract]  
Counterparty exposure $ 0
Conditional rights of set-off under ISDA Master Agreement reduce the maximum amount of loss due to credit risk $ 100,000