Derivative Financial Instruments - Impact of Derivatives on Consolidated Statements of Income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Cash Flow Hedges
Interest expense	$ 95,906	$ 136,020	$ 200,950	$ 310,837
Trading
Total	10,629	6,802	17,131	53,144
Designated as Hedging Instrument
Fair Value Hedges
Interest recognized on derivatives	22,857	19,433	45,467	24,056
Hedged items recorded in interest expense	20,948	2,296	52,224	(140,952)
Derivatives recorded in interest expense	(20,934)	(2,855)	(52,185)	141,328
Trading
Total	22,871	18,874	45,506	24,432
Designated as Hedging Instrument | Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent | Reclassification out of Accumulated Other Comprehensive Income
Cash Flow Hedges
Interest expense	(5,294)	(4,219)	(10,563)	(5,747)
Trading
Trading
Change in fair value of future interest payments recorded in earnings	(6,948)	(7,853)	(17,812)	34,459
Total	$ (6,948)	$ (7,853)	$ (17,812)	$ 34,459