Other Assets (Summary of Credit Loss Allowance) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Jun. 30, 2020	Dec. 31, 2020
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at January 1, 2020		$ 5,635
Loss provision for receivables	$ 81,600	187,128
Write-offs		(107,316)
Balance at December 31, 2020		$ 85,447