Description of Business and Summary of Significant Accounting Policies (Variable Interest Entity) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Variable Interest Entity [Line Items]
Assets	$ 5,022,311	$ 4,695,615
Liabilities	$ 2,668,352	$ 2,705,376
Variable Interest Entity, Primary Beneficiary
Variable Interest Entity [Line Items]
Ownership Percentage	40.00%
Assets	$ 17,000
Liabilities	$ 100