SCHEDULE II VALUATION AND QUALIFYING ACCOUNTS - Allowance for Doubtful Accounts (Details) - Allowance for Doubtful Accounts - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Movement in Valuation Allowances and Reserves
Balance at Beginning of Period	$ 48,450	$ 33,882	$ 34,889
Charges to Costs, Expenses and other	28,429	38,944	27,390
Write-off of Accounts Receivable	25,116	25,800	27,898
Other	(955)	1,424	(499)
Balance at End of Period	$ 50,808	$ 48,450	$ 33,882