Schedule II - Valuation and Qualifying Accounts (Details) - Allowance for Doubtful Accounts - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Year	$ 7,975	$ 12,919	$ 17,112
Additions	0	0	1,775
Deductions	2,889	4,944	5,968
Balance at End of Year	$ 5,086	$ 7,975	$ 12,919