Investments (Details-4) - ATC [Member] - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Related party transaction [Line Items]
Related party expenses	$ 32.0	$ 30.7	$ 30.4
Due from Related Parties	$ 7.0	$ 2.6

For an unclassified balance sheet, amounts due from related parties including affiliates, employees, joint ventures, officers and stockholders, immediate families thereof, and pension funds.

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+ Details