XML 104 R76.htm IDEA: XBRL DOCUMENT v3.19.3
Derivative Instruments and Hedging Activities - Components of Investment Fair Value Changes (Details) - USD ($)
$ in Thousands
3 Months Ended 9 Months Ended
Sep. 30, 2019
Sep. 30, 2018
Sep. 30, 2019
Sep. 30, 2018
Trading | Interest rate swaps        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Unrealized gains (losses) on derivatives $ (12,595) $ 2,275 $ (42,188) $ 16,379