Related Party Transactions (Debt Agreements) (Details) - Affiliated Entity - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Related Party Transaction [Line Items]
Short-term and Long-term debt	$ 0	$ 419,418
Prudential Insurance Loan Issued 4/20/2016
Related Party Transaction [Line Items]
Short-term and Long-term debt	$ 0	93,671
Interest Rate	3.47%
Prudential Insurance Loan Issued 4/20/2016
Related Party Transaction [Line Items]
Short-term and Long-term debt	$ 0	93,671
Interest Rate	4.39%
Prudential Insurance Loan Issued 4/20/2016
Related Party Transaction [Line Items]
Short-term and Long-term debt	$ 0	28,102
Interest Rate	4.39%
Prudential Insurance Loan Issued 4/20/2016
Related Party Transaction [Line Items]
Short-term and Long-term debt	$ 0	93,671
Interest Rate	3.95%
Prudential Insurance Loan Issued 4/20/2016
Related Party Transaction [Line Items]
Short-term and Long-term debt	$ 0	37,468
Interest Rate	3.95%
Prudential Insurance Loan Issued 4/20/2016
Related Party Transaction [Line Items]
Short-term and Long-term debt	$ 0	46,835
Interest Rate	3.95%
Prudential Insurance Loan Issued 6/28/2016
Related Party Transaction [Line Items]
Short-term and Long-term debt	$ 0	$ 26,000
Interest Rate	2.59%