Derivative Financial Instruments - Narrative (Details)	6 Months Ended
	Jun. 30, 2024 USD ($) counterparty	Dec. 31, 2023 USD ($)
Derivative [Line Items]
Number of central counterparties | counterparty	2
Notional value	$ 1,439,141,000	$ 1,906,092,000
Derivative, fair value, amount offset against collateral, net	6,000,000	9,000,000
Estimated accumulated gain (loss) to be reclassified in next 12 months	(29,000,000)
Cash collateral held relative to derivative exposure	0	0
Cash collateral pledged	6,000,000	$ 9,000,000
CME
Derivative [Line Items]
Notional value	$ 1,300,000,000
Percent of total notional derivative contracts	92.60%
Amount of variation margin included as settlement	$ (30,000,000)
LCH
Derivative [Line Items]
Notional value	$ 100,000,000
Percent of total notional derivative contracts	7.40%
Amount of variation margin included as settlement	$ (2,000,000)