Financial Derivatives - Narrative (Details) - USD ($)	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Derivative [Line Items]
Gain expected to be reclassified from AOCI to earnings over next 12 months	$ 7,200,000
Gain (loss) from interest rate swaps designated as cash flow hedges reclassified to earnings	0	$ 0
Investments held as collateral	0		$ 0
Financial derivatives in net payable position	0		0
Notional amount	20,416,319,000		17,547,367,000
Exchange Cleared
Derivative [Line Items]
Notional amount	16,900,000,000		14,900,000,000
Interest Rate Swap
Derivative [Line Items]
Notional amount	20,300,000,000		17,500,000,000
Cash
Derivative [Line Items]
Cash posted as collateral	105,300,000		16,600,000
Available-for-Sale Securities
Derivative [Line Items]
Cash posted as collateral	$ 182,900,000		$ 177,900,000