Derivatives - Additional Information (Details) - USD ($) $ in Thousands	1 Months Ended		3 Months Ended
	Mar. 31, 2020	Feb. 28, 2019	Mar. 31, 2020	Dec. 31, 2019
Derivative [Line Items]
Obligation to return cash collateral provided by counterparty	$ 19,100		$ 19,100
Derivative, notional amount	$ 2,517,457		2,517,457	$ 6,339,935
Deferred net gains (loss) on derivatives			$ (76,100)
Cash Flow Hedges
Derivative [Line Items]
Derivative, notional amount		$ 4,000,000
Derivative contract term		5 years
Derivative contract remaining maturity	4 years
Amortization period of gain reflected in other comprehensive income net of deferred income taxes	4 years
Realized gain on termination of cash flow hedges collar	$ 261,200
Maximum period for hedging transactions			5 years 10 months 24 days
LIBOR | Cash Flow Hedges
Derivative [Line Items]
Derivative fixed rate	0.5785%		0.5785%
Interest-bearing Deposits in Banks
Derivative [Line Items]
Cash or securities pledged as collateral	$ 13,200		$ 13,200	$ 10,600