Fair Value Measurements and Derivative Instruments (Credit Features) (Details) $ in Millions	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($) derivative
Derivative instruments disclosure
Number of derivatives requiring collateral to be posted | derivative		7
Collateral		$ 91.0
Interest contracts
Derivative instruments disclosure
Collateral		$ 57.3
Scenario, Forecast
Derivative instruments disclosure
Collateral	$ 33.3