Derivatives and Hedging Activity - Effect on Financial Statements (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Derivatives
Gain (loss) on derivative financial instruments, net	$ 41,812	$ (28,097)	$ 65,792	$ (34,485)
Interest rate contracts
Derivatives
Gain (loss) on derivative financial instruments, net	7,993	259	20,808	(52,129)
Interest rate swap guarantees
Derivatives
Gain (loss) on derivative financial instruments, net	(65)	260	431	(345)
Foreign exchange contracts
Derivatives
Gain (loss) on derivative financial instruments, net	33,796	(28,514)	44,857	17,644
Credit index instruments
Derivatives
Gain (loss) on derivative financial instruments, net	$ 88	$ (102)	$ (304)	$ 345