Summary of Significant Accounting Policies Change in Accounting Principle (Details) - Accounting Standards Update 2016-13 [Member]	Jan. 01, 2020 USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets	$ 2,300,000
Accounts Receivable, Allowance for Credit Loss	15,500,000
Reinsurance Recoverable, Allowance for Credit Loss	14,500,000
Total credit loss allowance relating to financial assets	$ 30,100,000